ItaniumManglingCanonicalizer - reduce StringRef.h include to forward declaration + remove duplicate includes. NFC

llvm/include/llvm/Support/ItaniumManglingCanonicalizer.h

@@ -14,11 +14,12 @@
 #ifndef LLVM_SUPPORT_ITANIUMMANGLINGCANONICALIZER_H
 #define LLVM_SUPPORT_ITANIUMMANGLINGCANONICALIZER_H
 
-#include "llvm/ADT/StringRef.h"
-
 #include <cstddef>
 
 namespace llvm {
+
+class StringRef;
+
 /// Canonicalizer for mangled names.
 ///
 /// This class allows specifying a list of "equivalent" manglings. For example,

llvm/lib/Support/ItaniumManglingCanonicalizer.cpp

@@ -7,16 +7,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/ItaniumManglingCanonicalizer.h"
-
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Demangle/ItaniumDemangle.h"
 #include "llvm/Support/Allocator.h"
 
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/FoldingSet.h"
-#include "llvm/ADT/StringRef.h"
-
 using namespace llvm;
 using llvm::itanium_demangle::ForwardTemplateReference;
 using llvm::itanium_demangle::Node;