Generated mappings are not assignable to trace-mapping AnyMap

[connor4312]

Trying to invoke new AnyMap(toDecodedMap(sourceMap)) gives the error:

Argument of type 'DecodedSourceMap' is not assignable to parameter of type 'SectionedSourceMapInput'.
  Type 'import("/Users/connor/Github/vscode-js-debug/node_modules/@jridgewell/gen-mapping/dist/types/types").DecodedSourceMap' is not assignable to type 'import("/Users/connor/Github/vscode-js-debug/node_modules/@jridgewell/trace-mapping/dist/types/types").DecodedSourceMap'.
    Types of property 'mappings' are incompatible.
      The type 'readonly SourceMapSegment[][]' is 'readonly' and cannot be assigned to the mutable type 'SourceMapSegment[][]'.

and try to invoke new AnyMap(toEncodedMap(sourceMap)) seems to fail to match the right union and just gives:

Argument of type 'EncodedSourceMap' is not assignable to parameter of type 'SectionedSourceMapInput'.
  Type 'EncodedSourceMap' is not assignable to type 'DecodedSourceMap'.
    Types of property 'mappings' are incompatible.
      Type 'string' is not assignable to type 'SourceMapSegment[][]'.

[jridgewell]

#20 should solve this.