[strong] Make strong 'this' optional for experimentation

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index 96c269546f755b6a706a4cc9d13b555453ad3d25..7e0c1a8aa629d8e60b9cacc6f56931bb7873f4cd 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -2563,7 +2563,8 @@ Statement* Parser::ParseExpressionOrLabelledStatement(
 
     case Token::THIS:
     case Token::SUPER:
-      if (is_strong(language_mode()) &&
+      if ((FLAG_strong_this || peek() != Token::THIS) &&

[conradw, 2015/06/12 15:01:34]

Could the peek() check be eliminated by shifting the flag check to if
(!FLAG_strong_this) { break; } in the THIS case with a fallthrough?

[rossberg, 2015/06/15 08:50:30]

Done.

+          is_strong(language_mode()) &&
           i::IsConstructor(function_state_->kind())) {
         bool is_this = peek() == Token::THIS;
         Expression* expr;