constify the Function parameter to the TTI creation callback and
propagate to all callers/users/etc.

llvm-svn: 247864
diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index 42f5fc9..2e869eb 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -182,8 +182,9 @@
 //===----------------------------------------------------------------------===//
 
 TargetIRAnalysis X86TargetMachine::getTargetIRAnalysis() {
-  return TargetIRAnalysis(
-      [this](Function &F) { return TargetTransformInfo(X86TTIImpl(this, F)); });
+  return TargetIRAnalysis([this](const Function &F) {
+    return TargetTransformInfo(X86TTIImpl(this, F));
+  });
 }