fix(es/minifier): Fix eval of toString of array with holes (#8727)

**Related issue:**

 - Closes #8717.

Author: kdy1

crates/swc_ecma_minifier/src/compress/pure/evaluate.rs

@@ -132,7 +132,10 @@ impl Pure<'_> {
                 return;
             }
 
-            if self.options.unsafe_passes && &*method_name.sym == "toString" && arr.elems.len() == 1
+            if self.options.unsafe_passes
+                && &*method_name.sym == "toString"
+                && arr.elems.len() == 1
+                && arr.elems[0].is_some()
             {
                 report_change!("evaluate: Reducing array.toString() call");
                 self.changed = true;

crates/swc_ecma_minifier/tests/fixture/issues/8717/config.json

@@ -0,0 +1,48 @@
+{
+    "defaults": true,
+    "arguments": false,
+    "arrows": true,
+    "booleans": true,
+    "booleans_as_integers": false,
+    "collapse_vars": true,
+    "comparisons": true,
+    "computed_props": true,
+    "conditionals": true,
+    "dead_code": true,
+    "directives": true,
+    "drop_console": false,
+    "drop_debugger": true,
+    "evaluate": true,
+    "expression": false,
+    "hoist_funs": false,
+    "hoist_props": true,
+    "hoist_vars": false,
+    "if_return": true,
+    "join_vars": true,
+    "keep_classnames": false,
+    "keep_fargs": true,
+    "keep_fnames": false,
+    "keep_infinity": false,
+    "loops": true,
+    "negate_iife": true,
+    "properties": true,
+    "reduce_funcs": false,
+    "reduce_vars": false,
+    "side_effects": true,
+    "switches": true,
+    "typeofs": true,
+    "unsafe": true,
+    "unsafe_arrows": false,
+    "unsafe_comps": false,
+    "unsafe_Function": false,
+    "unsafe_math": false,
+    "unsafe_symbols": false,
+    "unsafe_methods": false,
+    "unsafe_proto": false,
+    "unsafe_regexp": false,
+    "unsafe_undefined": false,
+    "unused": true,
+    "const_to_let": true,
+    "pristine_globals": true,
+    "passes": 3
+}

crates/swc_ecma_minifier/tests/fixture/issues/8717/input.js

@@ -0,0 +1 @@
+console.log([,].toString());

crates/swc_ecma_minifier/tests/fixture/issues/8717/output.js

@@ -0,0 +1,3 @@
+console.log([
+    , 
+].toString());