[DynInst_API:] [dyninst/dyninst] 8e4f8c: Start to fix stackwalk on ARM

[Xiaozhu Meng <noreply@xxxxxxxxxx>]

  Branch: refs/heads/ARMv8_stackwalk
  Home:   https://github.com/dyninst/dyninst
  Commit: 8e4f8ccf90c97eeeb5f64c1d30f889fcdb4ec25a
      https://github.com/dyninst/dyninst/commit/8e4f8ccf90c97eeeb5f64c1d30f889fcdb4ec25a
  Author: Xiaozhu Meng <xmeng@xxxxxxxxxxx>
  Date:   2019-02-27 (Wed, 27 Feb 2019)

  Changed paths:
    M dyninstAPI/src/stackwalk-aarch64.C
    M stackwalk/src/aarch64-swk.C
    M stackwalk/src/dbginfo-stepper.C
    M stackwalk/src/framestepper.C
    M stackwalk/src/linux-aarch64-swk.C

  Log Message:
  -----------
  Start to fix stackwalk on ARM
1. Fix signal handler stepper (assumes that ucontext is the first object of the frame)
2. Extend the function prologue matching range in FrameFuncStepper and delete unused previous frame check
3. Temporarily disable debug stepper because its implementation is wrong

Also DyninstAPI does propertly use stackwalkAPI:
1. DyninstAPI's own FrameFuncStepperHelper is wrong. Do not use it and use the default one in stackwalkAPI
2. DyninstAPI should also use SigHandlerStepper and BottomOfStackStepper


  Commit: c926d33bfd2cb3275aa0fc2cc9428dd6267cc068
      https://github.com/dyninst/dyninst/commit/c926d33bfd2cb3275aa0fc2cc9428dd6267cc068
  Author: Xiaozhu Meng <xmeng@xxxxxxxxxxx>
  Date:   2019-03-02 (Sat, 02 Mar 2019)

  Changed paths:
    M dyninstAPI/src/inst-aarch64.C
    M dyninstAPI/src/inst-aarch64.h
    M dyninstAPI/src/stackwalk-aarch64.C
    M stackwalk/src/aarch64-swk.C

  Log Message:
  -----------
  Fix stackwalk for instrumentation on ARM


Compare: https://github.com/dyninst/dyninst/compare/335da1ccb3c1...c926d33bfd2c