Fix issue with stack layout assumption going wrong when a dart function has optional parameters and…

vm/code_generator_ia32.cc

Index: vm/code_generator_ia32.cc
===================================================================
--- vm/code_generator_ia32.cc	(revision 7667)
+++ vm/code_generator_ia32.cc	(working copy)
@@ -546,6 +546,12 @@
     __ j(EQUAL, &all_arguments_processed, Assembler::kNearJump);
 
     __ Bind(&wrong_num_arguments);
+    if (locals_space_size() != 0) {
+      // We need to unwind the space we reserved for locals and copied
+      // parmeters. The NoSuchMethodFunction stub does not expect to
+      // see that area on the stack.
+      __ addl(ESP, Immediate(locals_space_size()));
+    }
     if (function.IsClosureFunction()) {
       GenerateCallRuntime(AstNode::kNoId,
                           0,