Revert "VM: New calling convention for generated code."

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index 85568b84046b5574860f0ae5cfb08b54122e8ffe..fe4fc6448d65d11a330040f6d3c0f3ad3662176d 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -758,9 +758,7 @@ static bool CompileParsedFunctionHelper(CompilationPipeline* pipeline,
         if (optimized) {
           // We may not have previous code if 'always_optimize' is set.
           if ((osr_id == Isolate::kNoDeoptId) && function.HasCode()) {
-            CodePatcher::PatchEntry(
-                Code::Handle(function.CurrentCode()),
-                Code::Handle(StubCode::FixCallersTarget_entry()->code()));
+            CodePatcher::PatchEntry(Code::Handle(function.CurrentCode()));
             if (FLAG_trace_compiler || FLAG_trace_patching) {
               if (FLAG_trace_compiler) {
                 THR_Print("  ");
@@ -792,6 +790,7 @@ static bool CompileParsedFunctionHelper(CompilationPipeline* pipeline,
           }
           function.set_unoptimized_code(code);
           function.AttachCode(code);
+          ASSERT(CodePatcher::CodeIsPatchable(code));
         }
         if (parsed_function->HasDeferredPrefixes()) {
           ASSERT(!FLAG_load_deferred_eagerly);