[RISCV] Re-enable JIT support

Commit 8922adf recently made JITTargetMachineBuilder honor the
hasJIT property of the target. LLVM supports just-in-time compilation
on RISC-V, so set the flag.

Differential Revision: https://reviews.llvm.org/D131617

llvm/lib/Target/RISCV/TargetInfo/RISCVTargetInfo.cpp

@@ -21,8 +21,8 @@ Target &llvm::getTheRISCV64Target() {
 }
 
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeRISCVTargetInfo() {
-  RegisterTarget<Triple::riscv32> X(getTheRISCV32Target(), "riscv32",
-                                    "32-bit RISC-V", "RISCV");
-  RegisterTarget<Triple::riscv64> Y(getTheRISCV64Target(), "riscv64",
-                                    "64-bit RISC-V", "RISCV");
+  RegisterTarget<Triple::riscv32, /*HasJIT=*/true> X(
+      getTheRISCV32Target(), "riscv32", "32-bit RISC-V", "RISCV");
+  RegisterTarget<Triple::riscv64, /*HasJIT=*/true> Y(
+      getTheRISCV64Target(), "riscv64", "64-bit RISC-V", "RISCV");
 }