1. Fix CFI for quick compiled code in x86 & x86_64;

2. Emit CFI in .eh_frame instead of .debug_frame.

With CFI, we can correctly unwind past quick generated code.
Now gdb should unwind to main() for both x86 & x86_64 host-side ART.

Note that it does not work with relocation yet.

Testing:
1. art/test/run-test --host --gdb [--64] --no-relocate 005
2. In gdb, run 'b art_quick_invoke_stub', then 'r', then 'c' a few times
3. In gdb, run 'bt'. You should see stack frames down to main()

Change-Id: I5350d4097dc3d360a60cb17c94f1d02b99bc58bb