[HPHPi] Use ParserBase::IsClosureName to check closure name

Summary:
Two places in HPHPi are changed to use ParserBase::IsClosureName to
check closure name to avoid ad-hoc code.

Test Plan: make fast_tests

Reviewers: mwilliams, qigao

Reviewed By: mwilliams

CC: hphp-diffs@lists, ps, mwilliams

Differential Revision: 351791

src/runtime/eval/ast/function_statement.cpp

@@ -101,7 +101,7 @@ int UserFunctionIdTable::getUserFunctionId(CStrRef func) {
 
 int UserFunctionIdTable::GetUserFunctionId(CStrRef func) {
   if (s_id >= RuntimeOption::MaxUserFunctionId) return -1;
-  if (func.data()[0] == '0') return -1; // closure
+  if (ParserBase::IsClosureName(func.data())) return -1;
   if (strncmp(func.data(), "lambda_", 7) == 0) return -1; // create_function
   return s_userFunctionIdTable->getUserFunctionId(func);
 }

src/runtime/eval/parser/parser.cpp

@@ -799,7 +799,7 @@ void Parser::onScalar(Token &out, int type, Token &scalar) {
     if (type == T_FUNC_C) subtype = T_FUNC_C;
     type = T_STRING;
     stext = haveFunc() ? peekFunc()->name() : "";
-    if (stext[0] == '0') {
+    if (ParserBase::IsClosureName(stext)) {
       stext = "{closure}";
     }
     break;