Arch-abstraction: made vg_execontext.c arch-independent, based on Paul
    Mackerras's work.

- introduced arch-neutral macros for getting the instruction/frame/stack
  pointers.

- renamed ExeContext.eips as ExeContext.ips

- renamed esp/ebp/eip to sp/fp/ip in several related files and arch-neutralised
  various comments

- introduced arch-neutral macros for walking the stack


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@2663 a5019735-40e9-0310-863c-91ae7b9d1cf9
6 files changed