dwarf/Gparser: fix crash during unwinding

dwarf/Gparser: fix crash during unwinding

We should update locations of the registers after all of them will
be restored. Otherwise some locations will be incorrect.

For example if function stores ebp, edi, esi and ebx registers on
stack in its prologue, compiler can generate following unwind info:
DW_CFA_expression: r5 (ebp) (DW_OP_breg5 (ebp): 0)
DW_CFA_expression: r7 (edi) (DW_OP_breg5 (ebp): -4)
DW_CFA_expression: r6 (esi) (DW_OP_breg5 (ebp): -8)
DW_CFA_expression: r3 (ebx) (DW_OP_breg5 (ebp): -12)

In this case locations of the ebx and ebp will be calculated using
current ebp but locations of the esi and edi will be calculated using
previous (restored) one. Due to it their locations will be incorrect
and it could lead to crash if we will try to get esi or edi value.

This patch fixes this problem.

Origin: https://github.com/libunwind/libunwind/pull/44
Change-Id: I33595d23fbbe034820461c2161f26e5285342ff8