X87: Remove frame pointer from StackHandler.

port 36e69a91 (r27115)

original commit message:

 This reduces the size of the StackHandler by yet another word. We no
 longer need to keep track of the frame pointer, as the stack walk will
 be able to recalculate it.

BUG=

Review URL: https://codereview.chromium.org/1030563002

Cr-Commit-Position: refs/heads/master@{#27357}

src/x87/macro-assembler-x87.cc

@@ -990,22 +990,16 @@ void MacroAssembler::LeaveApiExitFrame(bool restore_context) {
 void MacroAssembler::PushTryHandler(StackHandler::Kind kind,
                                     int handler_index) {
   // Adjust this code if not the case.
-  STATIC_ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
+  STATIC_ASSERT(StackHandlerConstants::kSize == 3 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
   STATIC_ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kContextOffset == 2 * kPointerSize);
-  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 3 * kPointerSize);
 
   // We will build up the handler from the bottom by pushing on the stack.
-  // First push the frame pointer and context.
+  // First push the context.
   if (kind == StackHandler::JS_ENTRY) {
-    // The frame pointer does not point to a JS frame so we save NULL for
-    // ebp. We expect the code throwing an exception to check ebp before
-    // dereferencing it to restore the context.
-    push(Immediate(0));  // NULL frame pointer.
     push(Immediate(Smi::FromInt(0)));  // No context.
   } else {
-    push(ebp);
     push(esi);
   }
   // Push the state.