Fix gcc.dg/torture/ssa-fre-{5,7}.c failure for avr

Fix gcc.dg/torture/ssa-fre-{5,7}.c failure for avr

The test assumes 32 bit integers (and pointers), and therefore
fails for the avr target, which has 16 bit integers.

Fix failure for avr by adding dg-require-effective-target int32.

gcc/testsuite/ChangeLog:

2019-08-02  Senthil Kumar Selvaraj  <senthilkumar.selvaraj@microchip.com>

	* gcc.dg/torture/ssa-fre-5.c: Add dg-require-effective-target int32.
	* gcc.dg/torture/ssa-fre-7.c: Likewise.

From-SVN: r274001