[llvm] [BOLT][RISCV] Implement basic instrumentation (PR #71664)

[Rafael Auler via llvm-commits]

================
@@ -0,0 +1,94 @@
+#ifndef LLVM_TOOLS_LLVM_BOLT_SYS_RISCV64
+#define LLVM_TOOLS_LLVM_BOLT_SYS_RISCV64
+
+#include <dirent.h>
----------------
rafaelauler wrote:

I was reading our current cmake file and we explicitly disable building the runtime if llvm is being cross-compiled. I imagine we would need to update the build rules to better support building the runtime for different scenarios.

https://github.com/llvm/llvm-project/pull/71664