X86: Clean up pass initialization

Summary:
- Remove redundant initializations from pass constructors that were
  already being initialized by LLVMInitializeX86Target().

- Add initialization function for the FPS pass.

Reviewers: craig.topper

Reviewed By: craig.topper

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63218

llvm-svn: 363221
diff --git a/llvm/lib/Target/X86/X86EvexToVex.cpp b/llvm/lib/Target/X86/X86EvexToVex.cpp
index e92fe4a..21ae1f1 100644
--- a/llvm/lib/Target/X86/X86EvexToVex.cpp
+++ b/llvm/lib/Target/X86/X86EvexToVex.cpp
@@ -68,9 +68,7 @@
 public:
   static char ID;
 
-  EvexToVexInstPass() : MachineFunctionPass(ID) {
-    initializeEvexToVexInstPassPass(*PassRegistry::getPassRegistry());
-  }
+  EvexToVexInstPass() : MachineFunctionPass(ID) { }
 
   StringRef getPassName() const override { return EVEX2VEX_DESC; }