PR tree-optimization/71625 - missing strlen optimization on different array

PR tree-optimization/71625 - missing strlen optimization on different array
initialization style (avoid compilation errors on aarch64)

gcc/ChangeLog:
	* config/aarch64/aarch64-builtins.c
	(aarch64_init_simd_builtin_types): Clear Poly8_t's TYPE_STRING_FLAG.

From-SVN: r263561

gcc/ChangeLog

+2018-08-15  Martin Sebor  <msebor@redhat.com>
+
+	PR tree-optimization/71625
+	* config/aarch64/aarch64-builtins.c
+	(aarch64_init_simd_builtin_types): Clear Poly8_t's TYPE_STRING_FLAG.
+
 2018-08-15  Ilya Leoshkevich  <iii@linux.ibm.com>
 
 	* config/s390/s390.c (s390_reorg): Remove loop.

gcc/config/aarch64/aarch64-builtins.c

@@ -643,6 +643,10 @@ aarch64_init_simd_builtin_types (void)
   /* Poly types are a world of their own.  */
   aarch64_simd_types[Poly8_t].eltype = aarch64_simd_types[Poly8_t].itype =
     build_distinct_type_copy (unsigned_intQI_type_node);
+  /* Prevent front-ends from transforming Poly8_t arrays into string
+     literals.  */
+  TYPE_STRING_FLAG (aarch64_simd_types[Poly8_t].eltype) = false;
+
   aarch64_simd_types[Poly16_t].eltype = aarch64_simd_types[Poly16_t].itype =
     build_distinct_type_copy (unsigned_intHI_type_node);
   aarch64_simd_types[Poly64_t].eltype = aarch64_simd_types[Poly64_t].itype =