Revert of Resolve references to "this" the same way as normal variables

src/arm/full-codegen-arm.cc

Index: src/arm/full-codegen-arm.cc
diff --git a/src/arm/full-codegen-arm.cc b/src/arm/full-codegen-arm.cc
index da385b62f699a43e92401c49b0c57f529800baeb..2522b09a68886257be64c5843fd77cb02a36ba94 100644
--- a/src/arm/full-codegen-arm.cc
+++ b/src/arm/full-codegen-arm.cc
@@ -127,7 +127,7 @@
   // global proxy when called as functions (without an explicit receiver
   // object).
   if (is_sloppy(info->language_mode()) && !info->is_native() &&
-      info->MayUseThis() && info->scope()->has_this_declaration()) {
+      info->MayUseThis()) {
     Label ok;
     int receiver_offset = info->scope()->num_parameters() * kPointerSize;
     __ ldr(r2, MemOperand(sp, receiver_offset));
@@ -216,9 +216,8 @@
     __ str(r0, MemOperand(fp, StandardFrameConstants::kContextOffset));
     // Copy any necessary parameters into the context.
     int num_parameters = info->scope()->num_parameters();
-    int first_parameter = info->scope()->has_this_declaration() ? -1 : 0;
-    for (int i = first_parameter; i < num_parameters; i++) {
-      Variable* var = (i == -1) ? scope()->receiver() : scope()->parameter(i);
+    for (int i = 0; i < num_parameters; i++) {
+      Variable* var = scope()->parameter(i);
       if (var->IsContextSlot()) {
         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
             (num_parameters - 1 - i) * kPointerSize;
@@ -3067,9 +3066,8 @@
   __ ldr(r4, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
 
   // r3: the receiver of the enclosing function.
-  Variable* this_var = scope()->LookupThis();
-  DCHECK_NOT_NULL(this_var);
-  __ ldr(r3, VarOperand(this_var, r3));
+  int receiver_offset = 2 + info_->scope()->num_parameters();
+  __ ldr(r3, MemOperand(fp, receiver_offset * kPointerSize));
 
   // r2: language mode.
   __ mov(r2, Operand(Smi::FromInt(language_mode())));