Use CodeSourceMap for stack traces (still JIT only).

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 69dc8146685755d55607dc1a7175e4df918de61e..8c7b8f8389ffe6ac167a79d08ea1cc336d52ef23 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -4784,6 +4784,10 @@ class Code : public Object {
   // function except the top-of-stack is the position of the call to the next
   // function. The stack will be empty if we lack the metadata to produce it,
   // which happens for stub code.
+  // The pc offset is interpreted as an instruction address (as needed by the
+  // disassembler or the top frame of a profiler sample), rather than a return
+  // address (as needed for a stack trace or the bottom frames of a profiler
+  // sample). Callers with a return address should subtract one.

[Florian Schneider, 2017/02/08 18:55:20]

Subtracting one from from pc_offset is a bit subtle. Maybe it would be better to
have two functions: GetInlinedFunctionsAtReturnAddress and
GetInlinedFunctionsAtPc?

[rmacnak, 2017/02/08 19:24:26]

Added GetInlinedFunctionsAtReturnAddress and switched the stack trace builder to
use it. Leaving the profiler as always using GetInlinedFunctionsAtPc because it
has its own cache based on instruction addresses 

   void GetInlinedFunctionsAt(
       intptr_t pc_offset,
       GrowableArray<const Function*>* functions,
@@ -8388,8 +8392,6 @@ class StackTrace : public Instance {
 
   intptr_t Length() const;
 
-  RawFunction* FunctionAtFrame(intptr_t frame_index) const;
-
   RawCode* CodeAtFrame(intptr_t frame_index) const;
   void SetCodeAtFrame(intptr_t frame_index, const Code& code) const;