RISC-V: Add riscv_vector.h wrapper in testsuite to prevent pull in st…

…dint.h from C library

For RISC-V linux/glibc toolchain will got header file not found when including
stdint.h if multilib is not enabled, it because some header file will
try to include gnu/stubs-<ABI-NAME>.h from the system, however it only
generated when multilib enabled.

In order to prevent that, we introduce a wrapper for riscv_vector.h,
include stdint-gcc.h rather than the default stdint.h.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/base/riscv_vector.h: New.

Reported-by: Christoph Müllner <christoph.muellner@vrull.eu>
Tested-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>

gcc/testsuite/gcc.target/riscv/rvv/base/riscv_vector.h

@@ -0,0 +1,11 @@
+/* Wrapper of riscv_vector.h, prevent riscv_vector.h including stdint.h from
+   C library, that might cause problem on testing RV32 related testcase when
+   we disable multilib.  */
+#ifndef _RISCV_VECTOR_WRAP_H
+
+#define _GCC_WRAP_STDINT_H
+#include "stdint-gcc.h"
+#include_next <riscv_vector.h>
+#define _RISCV_VECTOR_WRAP_H
+
+#endif