[RISCV] Drop '-x c' from riscv-target-features.c. NFC

Author: topperc

clang/test/Preprocessor/riscv-target-features.c

@@ -214,10 +214,10 @@
 // CHECK-A-EXT: __riscv_atomic 1
 
 // RUN: %clang --target=riscv32-unknown-linux-gnu \
-// RUN:   -march=rv32ib -x c -E -dM %s \
+// RUN:   -march=rv32ib -E -dM %s \
 // RUN:   -o - | FileCheck --check-prefix=CHECK-B-EXT %s
 // RUN: %clang --target=riscv64-unknown-linux-gnu \
-// RUN:   -march=rv64ib -x c -E -dM %s \
+// RUN:   -march=rv64ib -E -dM %s \
 // RUN:   -o - | FileCheck --check-prefix=CHECK-B-EXT %s
 // CHECK-B-EXT: __riscv_b 1000000{{$}}
 // CHECK-B-EXT: __riscv_zba 1000000{{$}}
@@ -793,9 +793,9 @@
 // RUN:   -o - | FileCheck --check-prefix=CHECK-ZALRSC-EXT %s
 // CHECK-ZALRSC-EXT: __riscv_zalrsc 1000000{{$}}
 
-// RUN: %clang --target=riscv32 -march=rv32izama16b -x c -E -dM %s \
+// RUN: %clang --target=riscv32 -march=rv32izama16b -E -dM %s \
 // RUN:   -o - | FileCheck --check-prefix=CHECK-ZAMA16B-EXT %s
-// RUN: %clang --target=riscv64 -march=rv64izama16b  -x c -E -dM %s \
+// RUN: %clang --target=riscv64 -march=rv64izama16b -E -dM %s \
 // RUN:   -o - | FileCheck --check-prefix=CHECK-ZAMA16B-EXT %s
 // CHECK-ZAMA16B-EXT: __riscv_zama16b  1000000{{$}}