Optimize AOT's switchable calls for the monomorphic case.

runtime/vm/stub_code_ia32.cc

Index: runtime/vm/stub_code_ia32.cc
diff --git a/runtime/vm/stub_code_ia32.cc b/runtime/vm/stub_code_ia32.cc
index 71cf7861e456cd8bca5271e38f72ea5dd84b0b30..15b8aa938e7e3b0037991a031f8be548314bc8de 100644
--- a/runtime/vm/stub_code_ia32.cc
+++ b/runtime/vm/stub_code_ia32.cc
@@ -2033,7 +2033,6 @@ void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
 //  EBX: receiver
 //  ECX: ICData (preserved)
 // Result:
-//  EBX: target entry point
 //  EDX: arguments descriptor
 void StubCode::GenerateICLookupThroughFunctionStub(Assembler* assembler) {
   __ int3();
@@ -2045,6 +2044,10 @@ void StubCode::GenerateICLookupThroughCodeStub(Assembler* assembler) {
 }
 
 
+void StubCode::GenerateMonomorphicMissStub(Assembler* assembler) {
+  __ int3();
+}
+
 
 void StubCode::GenerateFrameAwaitingMaterializationStub(Assembler* assembler) {
   __ int3();