testsuite: [arm/mve] Include arm_mve.h in arm_v8_1m_mve_ok

Since arm_mve.h includes stdint.h, its use requires the presence of
the right gnu/stub-*.h, so make sure to include it when checking the
arm_v8_1m_mve_ok_nocache effective target, otherwise we can decide MVE
is supported while it's not really. This makes several tests
unsupported rather than fail.

2020-04-22  Christophe Lyon  <christophe.lyon@linaro.org>

	gcc/testsuite/
	* lib/target-supports.exp
	(check_effective_target_arm_v8_1m_mve_ok_nocache): Include
	arm_mve.h.

gcc/testsuite/ChangeLog

 2020-04-22  Christophe Lyon  <christophe.lyon@linaro.org>
 
+        * lib/target-supports.exp
+        (check_effective_target_arm_v8_1m_mve_ok_nocache): Include
+        arm_mve.h.
+
+2020-04-22  Christophe Lyon  <christophe.lyon@linaro.org>
+
         * gcc.target/arm/mve/intrinsics/mve_vector_float.c: Use
         arm_v8_1m_mve_fp.
         * gcc.target/arm/mve/intrinsics/mve_vector_float1.c: Likewise.

gcc/testsuite/lib/target-supports.exp

@@ -4965,6 +4965,7 @@ proc check_effective_target_arm_v8_1m_mve_ok_nocache { } {
 	    #if __ARM_BIG_ENDIAN
 	    #error "MVE intrinsics are not supported in Big-Endian mode."
 	    #endif
+	    #include <arm_mve.h>
         } "$flags -mthumb"] } {
             set et_arm_v8_1m_mve_flags "$flags -mthumb --save-temps"
             return 1