X87: Remove receiver conversion from function prologue.

  port 4ab1b05d (r31826).

  original commit message:
  Depends on https://codereview.chromium.org/1407373007/
  After that CL, all receiver conversion is handled by the call builtin.

BUG=

Review URL: https://codereview.chromium.org/1419563006

Cr-Commit-Position: refs/heads/master@{#31849}

src/crankshaft/x87/lithium-codegen-x87.cc

@@ -107,26 +107,6 @@ bool LCodeGen::GeneratePrologue() {
     }
 #endif
 
-    // Sloppy mode functions and builtins need to replace the receiver with the
-    // global proxy when called as functions (without an explicit receiver
-    // object).
-    if (info()->MustReplaceUndefinedReceiverWithGlobalProxy()) {
-      Label ok;
-      // +1 for return address.
-      int receiver_offset = (scope()->num_parameters() + 1) * kPointerSize;
-      __ mov(ecx, Operand(esp, receiver_offset));
-
-      __ cmp(ecx, isolate()->factory()->undefined_value());
-      __ j(not_equal, &ok, Label::kNear);
-
-      __ mov(ecx, GlobalObjectOperand());
-      __ mov(ecx, FieldOperand(ecx, JSGlobalObject::kGlobalProxyOffset));
-
-      __ mov(Operand(esp, receiver_offset), ecx);
-
-      __ bind(&ok);
-    }
-
     if (support_aligned_spilled_doubles_ && dynamic_frame_alignment_) {
       // Move state of dynamic frame alignment into edx.
       __ Move(edx, Immediate(kNoAlignmentPadding));

src/full-codegen/x87/full-codegen-x87.cc

@@ -105,24 +105,12 @@ void FullCodeGenerator::Generate() {
   }
 #endif
 
-  // Sloppy mode functions and builtins need to replace the receiver with the
-  // global proxy when called as functions (without an explicit receiver
-  // object).
-  if (info->MustReplaceUndefinedReceiverWithGlobalProxy()) {
-    Label ok;
-    // +1 for return address.
+  if (FLAG_debug_code && info->ExpectsJSReceiverAsReceiver()) {
     int receiver_offset = (info->scope()->num_parameters() + 1) * kPointerSize;
     __ mov(ecx, Operand(esp, receiver_offset));
-
-    __ cmp(ecx, isolate()->factory()->undefined_value());
-    __ j(not_equal, &ok, Label::kNear);
-
-    __ mov(ecx, GlobalObjectOperand());
-    __ mov(ecx, FieldOperand(ecx, JSGlobalObject::kGlobalProxyOffset));
-
-    __ mov(Operand(esp, receiver_offset), ecx);
-
-    __ bind(&ok);
+    __ AssertNotSmi(ecx);
+    __ CmpObjectType(ecx, FIRST_SPEC_OBJECT_TYPE, ecx);
+    __ Assert(above_equal, kSloppyFunctionExpectsJSReceiverReceiver);
   }
 
   // Open a frame scope to indicate that there is a frame on the stack.  The