MIPS: Simplify pending message object handling.

Port d4696c48

Original commit message:
This moves the decision whether to report a message or not to when
the pending exception is propagated instead of trying to preserve the
decision in a ThreadLocalTop field.

BUG=

Review URL: https://codereview.chromium.org/1004623002

Cr-Commit-Position: refs/heads/master@{#27158}

src/mips/full-codegen-mips.cc

@@ -5329,26 +5329,12 @@ void FullCodeGenerator::EnterFinallyBlock() {
   __ li(at, Operand(pending_message_obj));
   __ lw(a1, MemOperand(at));
   __ push(a1);
-
-  ExternalReference has_pending_message =
-      ExternalReference::address_of_has_pending_message(isolate());
-  __ li(at, Operand(has_pending_message));
-  __ lw(a1, MemOperand(at));
-  __ SmiTag(a1);
-  __ push(a1);
 }
 
 
 void FullCodeGenerator::ExitFinallyBlock() {
   DCHECK(!result_register().is(a1));
   // Restore pending message from stack.
-  __ pop(a1);
-  __ SmiUntag(a1);
-  ExternalReference has_pending_message =
-      ExternalReference::address_of_has_pending_message(isolate());
-  __ li(at, Operand(has_pending_message));
-  __ sw(a1, MemOperand(at));
-
   __ pop(a1);
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());

src/mips64/full-codegen-mips64.cc

@@ -5331,26 +5331,12 @@ void FullCodeGenerator::EnterFinallyBlock() {
   __ li(at, Operand(pending_message_obj));
   __ ld(a1, MemOperand(at));
   __ push(a1);
-
-  ExternalReference has_pending_message =
-      ExternalReference::address_of_has_pending_message(isolate());
-  __ li(at, Operand(has_pending_message));
-  __ ld(a1, MemOperand(at));
-  __ SmiTag(a1);
-  __ push(a1);
 }
 
 
 void FullCodeGenerator::ExitFinallyBlock() {
   DCHECK(!result_register().is(a1));
   // Restore pending message from stack.
-  __ pop(a1);
-  __ SmiUntag(a1);
-  ExternalReference has_pending_message =
-      ExternalReference::address_of_has_pending_message(isolate());
-  __ li(at, Operand(has_pending_message));
-  __ sd(a1, MemOperand(at));
-
   __ pop(a1);
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());