[Clang] Enable RISC-V support for Fuchsia

We don't have a full sysroot yet, so for now we only include compiler
support and compiler-rt builtins, the rest of the runtimes will get
enabled later.

Differential Revision: https://reviews.llvm.org/D70477
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 664260d..c063f8c 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -383,6 +383,8 @@
     switch (os) {
     case llvm::Triple::FreeBSD:
       return new FreeBSDTargetInfo<RISCV64TargetInfo>(Triple, Opts);
+    case llvm::Triple::Fuchsia:
+      return new FuchsiaTargetInfo<RISCV64TargetInfo>(Triple, Opts);
     case llvm::Triple::Linux:
       return new LinuxTargetInfo<RISCV64TargetInfo>(Triple, Opts);
     default: