MIPS: Turn FastNewContextStub into a HydrogenCodeStub.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 00954b8e133c9e8d47b13f0e252d1ed85c84702a..dc1cd51c70a7ff3c84ae62eea6a34267f9cff66f 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -204,17 +204,18 @@ bool LCodeGen::GeneratePrologue() {
   if (heap_slots > 0) {
     Comment(";;; Allocate local context");
     // Argument to NewContext is the function, which is in a1.
-    __ push(a1);
     if (heap_slots <= FastNewContextStub::kMaximumSlots) {
       FastNewContextStub stub(heap_slots);
       __ CallStub(&stub);
     } else {
+      __ push(a1);
       __ CallRuntime(Runtime::kNewFunctionContext, 1);
     }
     RecordSafepoint(Safepoint::kNoLazyDeopt);
-    // Context is returned in both v0 and cp.  It replaces the context
-    // passed to us.  It's saved in the stack and kept live in cp.
-    __ sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+    // Context is returned in both v0. It replaces the context passed to us.
+    // It's saved in the stack and kept live in cp.
+    __ mov(cp, v0);
+    __ sw(v0, MemOperand(fp, StandardFrameConstants::kContextOffset));
     // Copy any necessary parameters into the context.
     int num_parameters = scope()->num_parameters();
     for (int i = 0; i < num_parameters; i++) {