Make FastNewFunctionContextStub take slots parameter

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

Index: src/crankshaft/mips/lithium-codegen-mips.cc
diff --git a/src/crankshaft/mips/lithium-codegen-mips.cc b/src/crankshaft/mips/lithium-codegen-mips.cc
index e2b781efa72b932193f833c9b0fa6d90f6204421..3389a3b10a77bf57e410b63ec217bc6cd2d5d76d 100644
--- a/src/crankshaft/mips/lithium-codegen-mips.cc
+++ b/src/crankshaft/mips/lithium-codegen-mips.cc
@@ -185,14 +185,12 @@ void LCodeGen::DoPrologue(LPrologue* instr) {
       __ Push(info()->scope()->GetScopeInfo(info()->isolate()));
       __ CallRuntime(Runtime::kNewScriptContext);
       deopt_mode = Safepoint::kLazyDeopt;
-    } else if (slots <= FastNewFunctionContextStub::kMaximumSlots) {
-      FastNewFunctionContextStub stub(isolate(), slots);
+    } else {
+      FastNewFunctionContextStub stub(isolate());
+      __ li(FastNewFunctionContextDescriptor::SlotsRegister(), Operand(slots));
       __ CallStub(&stub);
       // Result of FastNewFunctionContextStub is always in new space.
       need_write_barrier = false;
-    } else {
-      __ push(a1);
-      __ CallRuntime(Runtime::kNewFunctionContext);
     }
     RecordSafepoint(deopt_mode);