[RegAllocFast] Add the proper initialize method to use the .mir infrastructure

NFC

llvm-svn: 307427
diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp
index c606b7b..7d9bc8c 100644
--- a/llvm/lib/CodeGen/RegAllocFast.cpp
+++ b/llvm/lib/CodeGen/RegAllocFast.cpp
@@ -203,6 +203,8 @@
   char RAFast::ID = 0;
 }
 
+INITIALIZE_PASS(RAFast, "regallocfast", "Fast Register Allocator", false, false)
+
 /// getStackSpaceFor - This allocates space for the specified virtual register
 /// to be held on the stack.
 int RAFast::getStackSpaceFor(unsigned VirtReg, const TargetRegisterClass *RC) {