[turbofan] Various fixes to allow unboxed doubles as arguments in registers and on the stack.

src/compiler/arm64/code-generator-arm64.cc

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index 58adc2509883c6c5fcd002d1871c680136fae345..27d4889c34df5cca59ffeee94723d5116398ff06 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -184,12 +184,9 @@ class Arm64OperandConverter final : public InstructionOperandConverter {
 
   MemOperand ToMemOperand(InstructionOperand* op, MacroAssembler* masm) const {
     DCHECK(op != NULL);
-    DCHECK(!op->IsRegister());
-    DCHECK(!op->IsDoubleRegister());
     DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
-    // The linkage computes where all spill slots are located.
-    FrameOffset offset = linkage()->GetFrameOffset(
-        AllocatedOperand::cast(op)->index(), frame(), 0);
+    FrameOffset offset =
+        linkage()->GetFrameOffset(AllocatedOperand::cast(op)->index(), frame());
     return MemOperand(offset.from_stack_pointer() ? masm->StackPointer() : fp,
                       offset.offset());
   }
@@ -1118,6 +1115,8 @@ void CodeGenerator::AssemblePrologue() {
     __ StubPrologue();
     frame()->SetRegisterSaveAreaSize(
         StandardFrameConstants::kFixedFrameSizeFromFp);
+  } else {
+    frame()->SetPCOnStack(false);
   }
 
   if (info()->is_osr()) {
@@ -1149,6 +1148,7 @@ void CodeGenerator::AssemblePrologue() {
 void CodeGenerator::AssembleReturn() {
   CallDescriptor* descriptor = linkage()->GetIncomingDescriptor();
   int stack_slots = frame()->GetSpillSlotCount();
+  int pop_count = static_cast<int>(descriptor->StackParameterCount());
   if (descriptor->kind() == CallDescriptor::kCallAddress) {
     if (frame()->GetRegisterSaveAreaSize() > 0) {
       // Remove this frame's spill slots first.
@@ -1169,24 +1169,19 @@ void CodeGenerator::AssembleReturn() {
 
     __ Mov(csp, fp);
     __ Pop(fp, lr);
-    __ Ret();
   } else if (descriptor->IsJSFunctionCall() || needs_frame_) {
     // Canonicalize JSFunction return sites for now.
     if (return_label_.is_bound()) {
       __ B(&return_label_);
+      return;
     } else {
       __ Bind(&return_label_);
       __ Mov(jssp, fp);
       __ Pop(fp, lr);
-      int pop_count = static_cast<int>(descriptor->StackParameterCount());
-      if (pop_count != 0) {
-        __ Drop(pop_count);
-      }
-      __ Ret();
     }
-  } else {
-    __ Ret();
   }
+  __ Drop(pop_count);
+  __ Ret();
 }