fix(ivy): move setClassMetadata calls into a pure iife

This commit transforms the setClassMetadata calls generated by ngtsc from:

```typescript
/*@__PURE__*/ setClassMetadata(...);
```

to:

```typescript
/*@__PURE__*/ (function() {
  setClassMetadata(...);
})();
```

This is required for the build optimizer and side-effect-free analysis to
function correctly.

packages/compiler-cli/ngcc/test/rendering/renderer_spec.ts

@@ -198,10 +198,10 @@ A.ɵcmp = ɵngcc0.ɵɵdefineComponent({ type: A, selectors: [["a"]], decls: 1, v
     } if (rf & 2) {
         ɵngcc0.ɵɵtextInterpolate(ctx.person.name);
     } }, encapsulation: 2 });
-/*@__PURE__*/ ɵngcc0.ɵsetClassMetadata(A, [{
+/*@__PURE__*/ (function () { ɵngcc0.ɵsetClassMetadata(A, [{
         type: Component,
         args: [{ selector: 'a', template: '{{ person!.name }}' }]
-    }], null, null);`);
+    }], null, null); })();`);
       });
 
 
@@ -235,10 +235,10 @@ A.ɵcmp = ɵngcc0.ɵɵdefineComponent({ type: A, selectors: [["a"]], decls: 1, v
              expect(addDefinitionsSpy.calls.first().args[2])
                  .toEqual(`A.ɵfac = function A_Factory(t) { return new (t || A)(); };
 A.ɵdir = ɵngcc0.ɵɵdefineDirective({ type: A, selectors: [["", "a", ""]] });
-/*@__PURE__*/ ɵngcc0.ɵsetClassMetadata(A, [{
+/*@__PURE__*/ (function () { ɵngcc0.ɵsetClassMetadata(A, [{
         type: Directive,
         args: [{ selector: '[a]' }]
-    }], null, { foo: [] });`);
+    }], null, { foo: [] }); })();`);
            });
 
         it('should call removeDecorators with the source code, a map of class decorators that have been analyzed',
@@ -392,7 +392,7 @@ A.ɵdir = ɵngcc0.ɵɵdefineDirective({ type: A, selectors: [["", "a", ""]] });
               decorationAnalyses, switchMarkerAnalyses, privateDeclarationsAnalyses);
           const addDefinitionsSpy = testFormatter.addDefinitions as jasmine.Spy;
           expect(addDefinitionsSpy.calls.first().args[2])
-              .toContain(`/*@__PURE__*/ ɵngcc0.setClassMetadata(`);
+              .toContain(`/*@__PURE__*/ (function () { ɵngcc0.setClassMetadata(`);
           const addImportsSpy = testFormatter.addImports as jasmine.Spy;
           expect(addImportsSpy.calls.first().args[1]).toEqual([
             {specifier: './r3_symbols', qualifier: 'ɵngcc0'}
@@ -412,7 +412,7 @@ A.ɵdir = ɵngcc0.ɵɵdefineDirective({ type: A, selectors: [["", "a", ""]] });
               decorationAnalyses, switchMarkerAnalyses, privateDeclarationsAnalyses);
           const addDefinitionsSpy = testFormatter.addDefinitions as jasmine.Spy;
           expect(addDefinitionsSpy.calls.first().args[2])
-              .toContain(`/*@__PURE__*/ setClassMetadata(`);
+              .toContain(`/*@__PURE__*/ (function () { setClassMetadata(`);
           const addImportsSpy = testFormatter.addImports as jasmine.Spy;
           expect(addImportsSpy.calls.first().args[1]).toEqual([]);
         });

packages/compiler-cli/src/ngtsc/annotations/src/metadata.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Expression, ExternalExpr, FunctionExpr, Identifiers, InvokeFunctionExpr, LiteralArrayExpr, LiteralExpr, ReturnStatement, Statement, WrappedNodeExpr, literalMap} from '@angular/compiler';
+import {Expression, ExternalExpr, FunctionExpr, Identifiers, InvokeFunctionExpr, LiteralArrayExpr, LiteralExpr, NONE_TYPE, ReturnStatement, Statement, WrappedNodeExpr, literalMap} from '@angular/compiler';
 import * as ts from 'typescript';
 
 import {DefaultImportRecorder} from '../../imports';
@@ -74,11 +74,15 @@ export function generateSetClassMetadataCall(
         new WrappedNodeExpr(metaDecorators),
         metaCtorParameters,
         new WrappedNodeExpr(metaPropDecorators),
-      ],
+      ]);
+  const iifeFn = new FunctionExpr([], [fnCall.toStmt()], NONE_TYPE);
+  const iife = new InvokeFunctionExpr(
+      /* fn */ iifeFn,
+      /* args */[],
       /* type */ undefined,
       /* sourceSpan */ undefined,
       /* pure */ true);
-  return fnCall.toStmt();
+  return iife.toStmt();
 }
 
 /**

packages/compiler-cli/src/ngtsc/annotations/test/metadata_spec.ts

@@ -23,7 +23,7 @@ runInEachFileSystem(() => {
     @Component('metadata') class Target {}
     `);
       expect(res).toEqual(
-          `/*@__PURE__*/ i0.ɵsetClassMetadata(Target, [{ type: Component, args: ['metadata'] }], null, null);`);
+          `/*@__PURE__*/ (function () { i0.ɵsetClassMetadata(Target, [{ type: Component, args: ['metadata'] }], null, null); })();`);
     });
 
     it('should convert namespaced decorated class metadata', () => {
@@ -33,7 +33,7 @@ runInEachFileSystem(() => {
     @core.Component('metadata') class Target {}
     `);
       expect(res).toEqual(
-          `/*@__PURE__*/ i0.ɵsetClassMetadata(Target, [{ type: core.Component, args: ['metadata'] }], null, null);`);
+          `/*@__PURE__*/ (function () { i0.ɵsetClassMetadata(Target, [{ type: core.Component, args: ['metadata'] }], null, null); })();`);
     });
 
     it('should convert decorated class constructor parameter metadata', () => {

packages/compiler-cli/test/ngtsc/ngtsc_spec.ts

@@ -2614,6 +2614,21 @@ runInEachFileSystem(os => {
          expect(jsContents).toContain('directives: function () { return [CmpB]; }');
        });
 
+    it('should wrap setClassMetadata in an iife', () => {
+      env.write('test.ts', `
+        import {Injectable} from '@angular/core';
+
+        @Injectable({providedIn: 'root'})
+        export class Service {}
+      `);
+
+      env.driveMain();
+      const jsContents = env.getContents('test.js').replace(/\s+/g, ' ');
+      expect(jsContents)
+          .toContain(
+              `/*@__PURE__*/ (function () { i0.ɵsetClassMetadata(Service, [{ type: Injectable, args: [{ providedIn: 'root' }] }], null, null); })();`);
+    });
+
     it('should emit setClassMetadata calls for all types', () => {
       env.write('test.ts', `
       import {Component, Directive, Injectable, NgModule, Pipe} from '@angular/core';

packages/compiler/src/compiler.ts

@@ -78,7 +78,7 @@ export * from './ml_parser/tags';
 export {LexerRange} from './ml_parser/lexer';
 export * from './ml_parser/xml_parser';
 export {NgModuleCompiler} from './ng_module_compiler';
-export {ArrayType, AssertNotNull, DYNAMIC_TYPE, BinaryOperator, BinaryOperatorExpr, BuiltinMethod, BuiltinType, BuiltinTypeName, BuiltinVar, CastExpr, ClassField, ClassMethod, ClassStmt, CommaExpr, CommentStmt, ConditionalExpr, DeclareFunctionStmt, DeclareVarStmt, Expression, ExpressionStatement, ExpressionType, ExpressionVisitor, ExternalExpr, ExternalReference, literalMap, FunctionExpr, IfStmt, InstantiateExpr, InvokeFunctionExpr, InvokeMethodExpr, JSDocCommentStmt, LiteralArrayExpr, LiteralExpr, LiteralMapExpr, MapType, NotExpr, ReadKeyExpr, ReadPropExpr, ReadVarExpr, ReturnStatement, StatementVisitor, ThrowStmt, TryCatchStmt, Type, TypeVisitor, WrappedNodeExpr, WriteKeyExpr, WritePropExpr, WriteVarExpr, StmtModifier, Statement, STRING_TYPE, TypeofExpr, collectExternalReferences} from './output/output_ast';
+export {ArrayType, AssertNotNull, DYNAMIC_TYPE, BinaryOperator, BinaryOperatorExpr, BuiltinMethod, BuiltinType, BuiltinTypeName, BuiltinVar, CastExpr, ClassField, ClassMethod, ClassStmt, CommaExpr, CommentStmt, ConditionalExpr, DeclareFunctionStmt, DeclareVarStmt, Expression, ExpressionStatement, ExpressionType, ExpressionVisitor, ExternalExpr, ExternalReference, literalMap, FunctionExpr, IfStmt, InstantiateExpr, InvokeFunctionExpr, InvokeMethodExpr, JSDocCommentStmt, LiteralArrayExpr, LiteralExpr, LiteralMapExpr, MapType, NotExpr, NONE_TYPE, ReadKeyExpr, ReadPropExpr, ReadVarExpr, ReturnStatement, StatementVisitor, ThrowStmt, TryCatchStmt, Type, TypeVisitor, WrappedNodeExpr, WriteKeyExpr, WritePropExpr, WriteVarExpr, StmtModifier, Statement, STRING_TYPE, TypeofExpr, collectExternalReferences} from './output/output_ast';
 export {EmitterVisitorContext} from './output/abstract_emitter';
 export {JitEvaluator} from './output/output_jit';
 export * from './output/ts_emitter';