Fix ia32 build: there are no patchable calls on ia32

runtime/vm/flow_graph_compiler_ia32.cc

Index: runtime/vm/flow_graph_compiler_ia32.cc
diff --git a/runtime/vm/flow_graph_compiler_ia32.cc b/runtime/vm/flow_graph_compiler_ia32.cc
index 07678159e6a1ec49f27dcdd0bf8a080349cff9b2..d2ee67e74584ef18dee9bd776b13a5a952956265 100644
--- a/runtime/vm/flow_graph_compiler_ia32.cc
+++ b/runtime/vm/flow_graph_compiler_ia32.cc
@@ -1100,9 +1100,8 @@ void FlowGraphCompiler::GeneratePatchableCall(TokenPosition token_pos,
                                               const StubEntry& stub_entry,
                                               RawPcDescriptors::Kind kind,
                                               LocationSummary* locs) {

[Florian Schneider, 2016/11/16 20:37:03]

I'd rather remove this method, and replace the call-sites with GenerateCall.

This way, there will be a compile-time error if one want to generate a patchable
call on ia32.

[kustermann, 2016/11/16 20:45:32]

I can do that - though it's slightly weired since the FlowGraphCompiler will
still have the method declaration in the header file.

[Florian Schneider, 2016/11/16 20:50:13]

We do that already in many places. Sometimes we make the body just UNREACHABLE()
(e.g. if it is used a lot from architecture-independent code, but that's not the
case here)

-  __ CallPatchable(stub_entry);
-  AddCurrentDescriptor(kind, Thread::kNoDeoptId, token_pos);
-  RecordSafepoint(locs);
+  // No patchable calls on ia32.
+  GenerateCall(token_pos, stub_entry, kind, locs);
 }