[NFC] Add a new Intrinsics.cpp file for intrinsic code

Add new file Intrinsics.cpp and move `lookupLLVMIntrinsicByName`
to that file.

Author: jurahul

llvm/include/llvm/IR/Intrinsics.h

@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 //
 // This file defines a set of enums which allow processing of intrinsic
-// functions.  Values of these enum types are returned by
+// functions. Values of these enum types are returned by
 // Function::getIntrinsicID.
 //
 //===----------------------------------------------------------------------===//

llvm/lib/IR/CMakeLists.txt

@@ -32,6 +32,7 @@ add_llvm_component_library(LLVMCore
   GCStrategy.cpp
   GVMaterializer.cpp
   Globals.cpp
+  Intrinsics.cpp
   IRBuilder.cpp
   IRPrintingPasses.cpp
   SSAContext.cpp