RFR: 8066803: compiler/intrinsics/mathexact/SubExactINonConstantTest.java crashed in os::is_first_C_frame(frame*)

[Coleen Phillimore]

Summary: Stop native stack walk when we get to compiled or stub frame.

Coming from deoptimization, we hit a compiled frame (or deopt stub 
actually) in native memory tracking stack walking.  This code doesn't 
have the link pointer set up to match the native abi, so this crashes 
(sometimes).

open webrev at http://cr.openjdk.java.net/~coleenp/8066803/
bug link https://bugs.openjdk.java.net/browse/JDK-8066803

Ran test in the bug report 700 times (crashed within 8) with the fix.  
Also ran NMT tests.

Thanks,
Coleen