Symbol.metadata for decorators metadata proposal

Specification: proposal-decorator-metadata

Modules

esnext.symbol.metadata and esnext.function.metadata.

class Symbol {
  static metadata: @@metadata;
}

class Function {
  @@metadata: null;
}

CommonJS entry points

core-js/proposals/decorator-metadata-v2
core-js(-pure)/actual|full/symbol/metadata
core-js(-pure)/actual|full/function/metadata