[24/77] Replace a != BLKmode check with is_a <scalar_int_mode>

[24/77] Replace a != BLKmode check with is_a <scalar_int_mode>

This patch replaces a check against BLKmode with a check
of is_a <scalar_int_mode>, in a case where scalar integer
modes were the only useful alternatives left.

gcc/
2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

	* gimple-fold.c (gimple_fold_builtin_memory_op): Use
	is_a <scalar_int_mode> instead of != BLKmode.

From-SVN: r251476