[turbofan] Add basic support for calling to (a subset of) C functions.

src/compiler/code-generator.cc

Index: src/compiler/code-generator.cc
diff --git a/src/compiler/code-generator.cc b/src/compiler/code-generator.cc
index 38301c2d1a63107e9e243132190678f70f4811bb..8d4baa3145a3ce0fef9eaa409c861f91c5cf8e51 100644
--- a/src/compiler/code-generator.cc
+++ b/src/compiler/code-generator.cc
@@ -62,6 +62,11 @@ CodeGenerator::CodeGenerator(Frame* frame, Linkage* linkage,
 Handle<Code> CodeGenerator::GenerateCode() {
   CompilationInfo* info = this->info();
 
+  // Open a frame scope to indicate that there is a frame on the stack.  The
+  // MANUAL indicates that the scope shouldn't actually generate code to set up
+  // the frame (that is done in AssemblePrologue).
+  FrameScope frame_scope(masm(), StackFrame::MANUAL);
+
   // Emit a code line info recording start event.
   PositionsRecorder* recorder = masm()->positions_recorder();
   LOG_CODE_EVENT(isolate(), CodeStartLinePosInfoRecordEvent(recorder));