[test][ARM][CMSE] Use clang_cc1 in arm_cmse.h tests

Summary:
The `arm_cmse.h` header includes standard headers, but some tests that
include this header explicitly specify a target. The standard headers
found via the standard include paths need not be compatible with the
explicitly-specified target from the tests. In order to avoid test
failures caused by such incompatibility, this patch uses `%clang_cc1`,
which doesn't pick up the host system headers.

Reviewed By: chill

Differential Revision: https://reviews.llvm.org/D79693

clang/test/CodeGen/arm-cmse-nonsecure.c

@@ -1,5 +1,5 @@
-// RUN: %clang  -mlittle-endian -target thumbv8m.base-eabi  -emit-llvm -S -o - %s | FileCheck %s
-// RUN: %clang  -mbig-endian    -target thumbv8m.base-eabi  -emit-llvm -S -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple thumbv8m.base-unknown-unknown-eabi   -emit-llvm -mrelocation-model static -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple thumbebv8m.base-unknown-unknown-eabi -emit-llvm -mrelocation-model static -o - %s | FileCheck %s
 
 #include <arm_cmse.h>
 

clang/test/CodeGen/arm-cmse-secure.c

@@ -1,5 +1,5 @@
-// RUN: %clang -mlittle-endian -mcmse -target thumbv8m.base-eabi -emit-llvm -S -o - %s | FileCheck %s
-// RUN: %clang -mbig-endian    -mcmse -target thumbv8m.base-eabi -emit-llvm -S -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple thumbv8m.base-unknown-unknown-eabi   -emit-llvm -mrelocation-model static -mcmse -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple thumbebv8m.base-unknown-unknown-eabi -emit-llvm -mrelocation-model static -mcmse -o - %s | FileCheck %s
 
 #include <arm_cmse.h>