[clang] [RISCV] Install sifive_vector.h to riscv-resource-headers (PR #66330)

[Yueh-Ting Chen via cfe-commits]

================
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -triple riscv64 -target-feature +v %s
+// REQUIRES: riscv-registered-target
+
+// expected-no-diagnostics
+
+#include <sifive_vector.h>
----------------
eopXD wrote:

I think we can't :(

https://github.com/llvm/llvm-project/pull/66330