Fix static field initialization in optimzed DBC code.

runtime/vm/intermediate_language_dbc.cc

Index: runtime/vm/intermediate_language_dbc.cc
diff --git a/runtime/vm/intermediate_language_dbc.cc b/runtime/vm/intermediate_language_dbc.cc
index ec13a8339869a875de4b355bfe2cd7fdfb11c64e..5f986cb9104f38910a82ebce6ecc2ecd72a0d994 100644
--- a/runtime/vm/intermediate_language_dbc.cc
+++ b/runtime/vm/intermediate_language_dbc.cc
@@ -418,9 +418,13 @@ EMIT_NATIVE_CODE(LoadStaticField, 1, Location::RequiresRegister()) {
 }
 
 
-EMIT_NATIVE_CODE(InitStaticField, 0) {
-  ASSERT(!compiler->is_optimizing());
-  __ InitStaticTOS();
+EMIT_NATIVE_CODE(InitStaticField, 1) {
+  if (compiler->is_optimizing()) {
+    __ Push(locs()->in(0).reg());
+    __ InitStaticTOS();

[Vyacheslav Egorov (Google), 2016/11/09 09:28:28]

This looks like a call. Does this need compiler->RecordAfterCall(this)?

[Florian Schneider, 2016/11/09 13:51:52]

Actually yes, good point. It could throw, or cause a lazy deopt. 

Will deopt still work with the input pushed on the stack, or do I have to add a
InitStaticFieldOpt bytecode that takes a register as input?

[Vyacheslav Egorov (Google), 2016/11/09 13:55:11]

I think it should work. 

Maybe write a test?

+  } else {
+    __ InitStaticTOS();
+  }
 }