[Triple] Add test for if triple is RISC-V

[simoncook]

Summary

This is added as a helper/dependency for D54214, and I imagine other places will want to test for both RISC-V Triple architectures

[asb]

Thanks, added a test and applied.

llvm/trunk/include/llvm/ADT/Triple.h

bool isMIPS() const {
     return isMIPS32() || isMIPS64();
   }
 
   /// Tests whether the target is 64-bit PowerPC (little and big endian).
   bool isPPC64() const {
     return getArch() == Triple::ppc64 || getArch() == Triple::ppc64le;
   }
 
+  /// Tests whether the target is RISC-V (32- and 64-bit).
+  bool isRISCV() const {
+    return getArch() == Triple::riscv32 || getArch() == Triple::riscv64;
+  }
+
   /// Tests whether the target supports comdat
   bool supportsCOMDAT() const {
     return !isOSBinFormatMachO();
   }
 
   /// Tests whether the target uses emulated TLS as default.
   bool hasDefaultEmulatedTLS() const {
     return isAndroid() || isOSOpenBSD() || isWindowsCygwinEnvironment();

llvm/trunk/unittests/ADT/TripleTest.cpp

TEST(TripleTest, BitWidthPredicates) {
   EXPECT_FALSE(T.isArch16Bit());
   EXPECT_TRUE(T.isArch32Bit());
   EXPECT_FALSE(T.isArch64Bit());
 
   T.setArch(Triple::riscv32);
   EXPECT_FALSE(T.isArch16Bit());
   EXPECT_TRUE(T.isArch32Bit());
   EXPECT_FALSE(T.isArch64Bit());
+  EXPECT_TRUE(T.isRISCV());
 
   T.setArch(Triple::riscv64);
   EXPECT_FALSE(T.isArch16Bit());
   EXPECT_FALSE(T.isArch32Bit());
   EXPECT_TRUE(T.isArch64Bit());
+  EXPECT_TRUE(T.isRISCV());
 }
 
 TEST(TripleTest, BitWidthArchVariants) {
   Triple T;
   EXPECT_EQ(Triple::UnknownArch, T.get32BitArchVariant().getArch());
   EXPECT_EQ(Triple::UnknownArch, T.get64BitArchVariant().getArch());
 
   T.setArch(Triple::UnknownArch);