Restore fp after calling JNI method in allstubs interpreter

The allstubs interpreter uses self->interpSave.curFrame as fp.
The invokeMethod native code sets self->interpSave.curFrame directly
effectively updating fp, so restore fp after the call has completed.

original Id: I0ffb15b71a48c2780251bbcd66e551bb0a52fe94
Signed-off-by: Chris Dearman <chris@mips.com>

Conflicts:

	vm/mterp/c/gotoTargets.c
	vm/mterp/out/InterpC-allstubs.c
	vm/mterp/out/InterpC-portdbg.c
	vm/mterp/out/InterpC-x86-atom.c
	vm/mterp/out/InterpC-x86.c
resolved:) and adapted to gingerbread

picked from
https://android-review.googlesource.com/#/c/31824/
Merge "Restore fp after calling JNI method in allstubs interpreter" into gingerbread