Fix issue 18834. Collect stack trace before the frame is prepared for OSR.

runtime/vm/debugger.cc

Index: runtime/vm/debugger.cc
===================================================================
--- runtime/vm/debugger.cc	(revision 36356)
+++ runtime/vm/debugger.cc	(working copy)
@@ -1186,22 +1186,12 @@
 ActivationFrame* Debugger::CollectDartFrame(Isolate* isolate,
                                             uword pc,
                                             StackFrame* frame,
-                                            const Code& code_param,
+                                            const Code& code,
                                             const Array& deopt_frame,
                                             intptr_t deopt_frame_offset,
                                             ActivationFrame* callee_activation,
                                             const Context& entry_ctx) {
-  // TODO(turnidge): Remove the workaround below once...
-  //    https://code.google.com/p/dart/issues/detail?id=18384
-  // ...is fixed.
-  Code& code = Code::Handle(isolate);
-  code = code_param.raw();
-  if (!code.ContainsInstructionAt(pc)) {
-    code = Code::LookupCode(pc);
-    ASSERT(!code.IsNull());
-    ASSERT(code.ContainsInstructionAt(pc));
-  }
-
+  ASSERT(code.ContainsInstructionAt(pc));
   // We provide either a callee activation or an entry context.  Not both.
   ASSERT(((callee_activation != NULL) && entry_ctx.IsNull()) ||
          ((callee_activation == NULL) && !entry_ctx.IsNull()));