Check mask argument's type when vectorising conditional functions

Check mask argument's type when vectorising conditional functions

We can't yet vectorise conditional internal functions whose boolean
condition is fed by a data access (or more generally, by a tree of logic
ops in which all the leaves are data accesses).  Although we should add
that eventually, we'd need further work to generate good-quality code.

Unlike vectorizable_load and vectorizalbe_store, vectorizable_call
wasn't checking whether the mask had a suitable type, leading to an
ICE on the testcases.

2020-01-06  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vect-stmts.c (vect_check_load_store_mask): Rename to...
	(vect_check_scalar_mask): ...this.
	(vectorizable_store, vectorizable_load): Update call accordingly.
	(vectorizable_call): Use vect_check_scalar_mask to check the mask
	argument in calls to conditional internal functions.

gcc/testsuite/
	* gcc.dg/vect/vect-cond-arith-8.c: New test.
	* gcc.target/aarch64/sve/cond_fmul_5.c: Likewise.

From-SVN: r279907