Do not compile the unreachable body of functions with illegal redeclarations.

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
index d3f54ad3f2d9ad8b47fefae2d89fd692bd3e2eda..fd573b03b8bd72cc924aaf24970d4693f31c6b52 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -383,8 +383,7 @@ void Scope::AddDeclaration(Declaration* declaration) {
 
 
 void Scope::SetIllegalRedeclaration(Expression* expression) {
-  // Only set the illegal redeclaration expression the
-  // first time the function is called.
+  // Record only the first illegal redeclaration.
   if (!HasIllegalRedeclaration()) {
     illegal_redecl_ = expression;
   }