[RISCV] Mark unit tests as "requires: riscv-registered-target"

Some of these tests break if the RISCV backend has not been built.

Reland D54816.

llvm-svn: 347720

clang/test/Driver/riscv-abi.c

@@ -1,3 +1,5 @@
+// REQUIRES: riscv-registered-target
+
 // RUN: %clang -target riscv32-unknown-elf %s -### -o %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-ILP32 %s
 // RUN: %clang -target riscv32-unknown-elf %s -### -o %t.o -mabi=ilp32 2>&1 \

clang/test/Driver/riscv-arch.c

@@ -1,3 +1,5 @@
+// REQUIRES: riscv-registered-target
+
 // RUN: %clang -target riscv32-unknown-elf -march=rv32i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck %s
 // RUN: %clang -target riscv32-unknown-elf -march=rv32im -### %s \

clang/test/Driver/riscv-features.c

@@ -1,3 +1,5 @@
+// REQUIRES: riscv-registered-target
+
 // RUN: %clang -target riscv32-unknown-elf -### %s -fsyntax-only 2>&1 | FileCheck %s
 // RUN: %clang -target riscv64-unknown-elf -### %s -fsyntax-only 2>&1 | FileCheck %s
 

clang/test/Driver/riscv-gnutools.c

@@ -1,3 +1,5 @@
+// REQUIRES: riscv-registered-target
+
 // Check gnutools are invoked with propagated values for -mabi and -march.
 
 // RUN: %clang -target riscv32 -fno-integrated-as %s -###  -c \

clang/test/Driver/riscv32-toolchain.c

@@ -1,3 +1,5 @@
+// REQUIRES: riscv-registered-target
+
 // A basic clang -cc1 command-line, and simple environment check.
 
 // RUN: %clang %s -### -no-canonical-prefixes -target riscv32 2>&1 | FileCheck -check-prefix=CC1 %s

clang/test/Driver/riscv64-toolchain.c

@@ -1,3 +1,5 @@
+// REQUIRES: riscv-registered-target
+
 // A basic clang -cc1 command-line, and simple environment check.
 
 // RUN: %clang %s -### -no-canonical-prefixes -target riscv64 2>&1 | FileCheck -check-prefix=CC1 %s