perf: remove comments from js-files (#3760)

Strip comments from all .js files (except legacy-reexports and compat) while retaining them for .d.ts files. The legacy-reexport does not have any comments and will be removed with compat in next major version.

```
npx get-folder-size --folder=dist/package
// 5.88 Mb (with comments)
// 4.63 Mb (without comments)
```

Roughly 1.25 Mb is saved by removing comments.

package.json

@@ -41,14 +41,15 @@
   "scripts": {
     "precommit": "lint-staged",
     "commitmsg": "validate-commit-msg",
-    "build_all": "npm-run-all compat_build_all clean_dist copy_sources build_cjs build_esm5 build_esm2015 build_esm5_for_rollup build_umd build_legacy_reexport build_migrations generate_packages copy_for_tests",
+    "build_all": "npm-run-all compat_build_all clean_dist copy_sources build_cjs build_esm5 build_esm2015 build_esm5_for_rollup build_umd build_types build_legacy_reexport build_migrations generate_packages copy_for_tests",
     "build_cjs": "npm-run-all clean_dist_cjs compile_dist_cjs",
     "build_esm5": "npm-run-all clean_dist_esm5 compile_dist_esm5",
     "build_esm5_for_rollup": "npm-run-all clean_dist_esm5_for_rollup compile_dist_esm5_for_rollup && mkdirp dist/esm5_for_rollup/node_modules && shx cp -r ./dist-compat/package ./dist/esm5_for_rollup/node_modules/rxjs-compat",
     "build_esm2015": "npm-run-all clean_dist_esm2015 compile_dist_esm2015",
     "build_esm2015_for_docs": "npm-run-all clean_dist_esm2015 compile_dist_esm2015_for_docs",
     "build_legacy_reexport": "npm-run-all compile_legacy_reexport",
     "build_migrations": "npm-run-all clean_dist_migrations compile_dist_migrations",
+    "build_types": "npm-run-all clean_dist_types compile_dist_types",
     "build_closure_core": "node ./tools/make-closure-core.js",
     "build_global": "npm-run-all clean_dist_global build_esm5_for_rollup && mkdirp ./dist/global && node ./tools/make-umd-bundle.js && npm-run-all build_closure_core clean_dist_esm5_for_rollup",
     "build_umd": "npm-run-all clean_dist_global && mkdirp ./dist/global && node ./tools/make-umd-bundle.js && npm-run-all build_closure_core",
@@ -64,13 +65,15 @@
     "clean_dist_esm2015": "shx rm -rf ./dist/esm2015",
     "clean_dist_global": "shx rm -rf ./dist/global",
     "clean_dist_migrations": "shx rm -rf ./dist/migrations",
+    "clean_dist_types": "shx rm -rf ./dist/typings",
     "commit": "git-cz",
     "compile_dist_cjs": "tsc -p ./tsconfig/tsconfig.cjs.json",
     "compile_dist_esm5": "tsc -p ./tsconfig/tsconfig.esm5.json",
     "compile_dist_esm2015": "tsc -p ./tsconfig/tsconfig.esm2015.json",
     "compile_dist_esm2015_for_docs": "tsc ./dist/src/internal/Rx.ts ./dist/src/add/observable/of.ts ./dist/src/MiscJSDoc.ts -m es2015   --sourceMap --outDir ./dist/es6 --target es2015 -d --diagnostics --pretty --noImplicitAny --noImplicitReturns --noImplicitThis --suppressImplicitAnyIndexErrors --moduleResolution node",
     "compile_dist_esm5_for_rollup": "tsc -p ./tsconfig/tsconfig.esm5.rollup.json",
     "compile_dist_migrations": "tsc -p ./tsconfig/tsconfig.migrations.json",
+    "compile_dist_types": "tsc -p ./tsconfig/tsconfig.types.json",
     "compile_legacy_reexport": "tsc -p ./tsconfig/tsconfig.legacy-reexport.json",
     "copy_sources": "mkdirp dist && shx cp -r ./src/ ./dist/src",
     "copy_for_tests": "shx rm -rf ./spec-build && shx cp -r ./spec/ ./spec-build/ && mkdirp ./spec-build/node_modules && shx cp -r ./dist/package/ ./spec-build/node_modules/rxjs && shx cp -r ./dist-compat/package/ ./spec-build/node_modules/rxjs-compat",

tsconfig.base.json

@@ -1,6 +1,6 @@
 {
   "compilerOptions": {
-    "removeComments": false,
+    "removeComments": true,
     "preserveConstEnums": true,
     "sourceMap": true,
     "strictFunctionTypes": true,

tsconfig/compat/tsconfig.cjs.json

@@ -3,6 +3,7 @@
   "compilerOptions": {
     "module": "commonjs",
     "target": "es5",
+    "removeComments": false,
     "declaration": true,
     "declarationDir": "../../dist-compat/typings",
     "outDir": "../../dist-compat/cjs"

tsconfig/tsconfig.cjs.json

@@ -3,8 +3,6 @@
   "compilerOptions": {
     "module": "commonjs",
     "target": "es5",
-    "declaration": true,
-    "declarationDir": "../dist/typings",
     "outDir": "../dist/cjs"
   }
 }

tsconfig/tsconfig.legacy-reexport.json

@@ -3,6 +3,7 @@
   "compilerOptions": {
     "module": "commonjs",
     "target": "es5",
+    "removeComments": false,
     "declaration": true,
     "noEmit": false,
     "outDir": "../dist/legacy-reexport",

tsconfig/tsconfig.types.json

@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.base.json",
+  "compilerOptions": {
+    "module": "es2015",
+    "target": "esnext",
+    "removeComments": false,
+    "declaration": true,
+    "declarationDir": "../dist/typings",
+    "emitDeclarationOnly": true
+  }
+}