[binutils-gdb] Use bool in pv_area

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT a900ff724a725ea951ba8b17232577e1a4b4866e ***

Author: Tom Tromey <tom@tromey.com>
Branch: master
Commit: a900ff724a725ea951ba8b17232577e1a4b4866e

Use bool in pv_area

This updates a couple of member functions in pv_area to return bool.

gdb/ChangeLog
2017-10-12  Tom Tromey  <tom@tromey.com>

	* prologue-value.h (pv_area::store_would_trash): Return bool.
	(pv_area::find_reg): Likewise.
	* prologue-value.c (pv_area::store_would_trash): Return bool.
	(pv_area::find_reg): Likewise.