Fix bogus pr64277.c failure for avr

Fix bogus pr64277.c failure for avr

The smaller int size for the avr target breaks the test's
expectation on the number of iterations. The failure goes
away if 32 bit ints are used in place of a plain int.

Fix by conditionally typedef int32_t to __INT32_TYPE__ for targets
with int size < 4,  and then use int32_t everywhere.

gcc/testsuite
016-11-25  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>

	* gcc.dg/pr64277.c: Use __INT32_TYPE__ for targets
	with sizeof(int) < 4.

From-SVN: r242859