Moved the variable VGOFF_(m_eip) from x86, and moved it (and its
computation) into the generic core, because it's needed by the dispatch
loop of all archs.  Also renamed it VG_(instr_ptr_offset), which is
clearer.  Since it was the last use of the VGOFF_ prefix, I removed that
prefix.  

Also cleaned up the ARM stubs slightly, by removing some of the copied,
commented-out x86 code which has since fallen out of date with the real
x86 code and was thus misleading.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@3123 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/core.h b/coregrind/core.h
index 4d4dd92..32eb3fd 100644
--- a/coregrind/core.h
+++ b/coregrind/core.h
@@ -1239,6 +1239,9 @@
 /* Counts downwards in vg_run_innerloop. */
 extern UInt VG_(dispatch_ctr);
 
+// Instruction pointer guest state offset, used by $VG_ARCH/dispatch.S.
+extern UInt VG_(instr_ptr_offset);
+
 /* --- Counters, for informational purposes only. --- */
 
 // These counters must be declared here because they're maintained by
@@ -1753,7 +1756,7 @@
 #define PTHREQ_RET(regs)   ((regs).vex.ARCH_PTHREQ_RET)
 #define CLREQ_RET(regs)    ((regs).vex.ARCH_CLREQ_RET)
 
-// Offsets for the shadow state
+// Offsets for the Vex state
 #define O_STACK_PTR        (offsetof(VexGuestArchState, ARCH_STACK_PTR))
 #define O_FRAME_PTR        (offsetof(VexGuestArchState, ARCH_FRAME_PTR))