Hello,

If the GDB configure script finds sys/procfs.h and the prfpregset_t
type, it checks whether prfpregset_t is usable, setting
PRFPREGSET_T_BROKEN if so. It does this using AC_TRY_RUN to test the
value of sizeof(prfregset_t). This doesn't work for cross-compiled
builds so for those PRFPREGSET_T_BROKEN is always set.

This patch replaces the use of AC_TRY_RUN with a test that uses
AC_CHECK_SIZEOF to decide whether to set PRFPREGSET_T_BROKEN. This can
be run for cross-compiled builds.

Tested by cross-compiling for aarch64-none-linux-gnu and recent
glibc and by building with the logic inverted, to check the conditional was
correctly executing. Also by building for native x86_64-none-linux-gnu.

Ok for trunk?
Matthew

gdb/
2016-09-26  Matthew Wahab  <matthew.wahab@arm.com>

	* configure.ac (PRFPREGSET_T_BROKEN): Replace AC_TRY_RUN test with
	AC_CHECK_SIZEOF.
	* configure: Regenerate.