Drop IsPregenerated() and allow_stub_calls flag.

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
diff --git a/src/ia32/macro-assembler-ia32.cc b/src/ia32/macro-assembler-ia32.cc
index b5cefdbc1a4e5ece50e6195410124d9c4fa4b5cd..dd1e8e63088b28b01400faccc2f71e464570a6a5 100644
--- a/src/ia32/macro-assembler-ia32.cc
+++ b/src/ia32/macro-assembler-ia32.cc
@@ -46,7 +46,6 @@ namespace internal {
 MacroAssembler::MacroAssembler(Isolate* arg_isolate, void* buffer, int size)
     : Assembler(arg_isolate, buffer, size),
       generating_stub_(false),
-      allow_stub_calls_(true),
       has_frame_(false) {
   if (isolate() != NULL) {
     // TODO(titzer): should we just use a null handle here instead?
@@ -2188,8 +2187,6 @@ void MacroAssembler::CallStub(CodeStub* stub, TypeFeedbackId ast_id) {
 
 
 void MacroAssembler::TailCallStub(CodeStub* stub) {
-  ASSERT(allow_stub_calls_ ||
-         stub->CompilingCallsToThisStubIsGCSafe(isolate()));
   jmp(stub->GetCode(isolate()), RelocInfo::CODE_TARGET);
 }
 
@@ -2201,8 +2198,7 @@ void MacroAssembler::StubReturn(int argc) {
 
 
 bool MacroAssembler::AllowThisStubCall(CodeStub* stub) {
-  if (!has_frame_ && stub->SometimesSetsUpAFrame()) return false;
-  return allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe(isolate());
+  return has_frame_ || !stub->SometimesSetsUpAFrame();
 }