[es6] Check declaration conflicts between non-simple parameters and the function body

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index c1ae28577974f5e91f9aa87864bdcd7b6886e46c..5dd0f9035160b2cf5044dec5d45a1fbfbb59b033 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -4443,6 +4443,9 @@ ZoneList<Statement*>* Parser::ParseEagerFunctionBody(
 
     inner_scope->set_end_position(scanner()->location().end_pos);
     inner_scope = inner_scope->FinalizeBlockScope();
+    if (inner_scope != nullptr) {
+      CheckConflictingVarDeclarations(inner_scope, CHECK_OK);
+    }
 
     result->Add(init_block, zone());
     result->Add(inner_block, zone());