Bug 1577857 - Create ParseInfo class to manage Parser related information r=tcampbell

- Hoists the UsedNameTracker and and the FunctionTreeHolder into a new ParseInfo structure.
- Make LifoAllocScopes lifetimes lexically explicit throughout parser.
- Removes allocator argument to Parser construction in lieu of the LifoAllocScope inside of ParseInfo.

Differential Revision: https://phabricator.services.mozilla.com/D45042

js/src/frontend/BinASTParserPerTokenizer.cpp

@@ -83,14 +83,14 @@ using UsedNamePtr = UsedNameTracker::UsedNameMap::Ptr;
 
 template <typename Tok>
 BinASTParserPerTokenizer<Tok>::BinASTParserPerTokenizer(
-    JSContext* cx, LifoAlloc& alloc, UsedNameTracker& usedNames,
+    JSContext* cx, ParseInfo& parseInfo,
     const JS::ReadOnlyCompileOptions& options,
     HandleScriptSourceObject sourceObject,
     Handle<LazyScript*> lazyScript /* = nullptr */)
-    : BinASTParserBase(cx, alloc, usedNames, sourceObject),
+    : BinASTParserBase(cx, parseInfo, sourceObject),
       options_(options),
       lazyScript_(cx, lazyScript),
-      handler_(cx, alloc, nullptr, SourceKind::Binary),
+      handler_(cx, parseInfo.allocScope.alloc(), nullptr, SourceKind::Binary),
       variableDeclarationKind_(VariableDeclarationKind::Var),
       treeHolder_(cx, FunctionTreeHolder::Mode::Eager) {
   MOZ_ASSERT_IF(lazyScript_, lazyScript_->isBinAST());