Clear hard frame pointer alignment if not needed

When hard frame pointer isn't needed, the register for hard frame pointer
may be reused.  This patch clears alignment on hard frame pointer if hard
frame pointer isn't needed.

gcc/

	PR rtl-optimization/64905
	* lra-eliminations.c (setup_can_eliminate): Clear hard frame
	pointer alignment if it isn't needed.

gcc/testsuite/

	PR rtl-optimization/64905
	* gcc.target/i386/pr64905.c: New file.

From-SVN: r220414

gcc/ChangeLog

+2015-02-04  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR rtl-optimization/64905
+	* lra-eliminations.c (setup_can_eliminate): Clear hard frame
+	pointer alignment if it isn't needed.
+
 2015-02-04  Matthew Wahab  <matthew.wahab@arm.com>
 
 	* config/aarch64/aarch64-cores.def: Add cortex-a72 and

gcc/testsuite/ChangeLog

+2015-02-04  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR rtl-optimization/64905
+	* gcc.target/i386/pr64905.c: New file.
+
 2015-02-04  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* gcc.dg/guality/pr41447-1.c: Remove xfail.