Pass StringRef by value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86251 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index b4ce1d7..ceb0505 100644
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -21,8 +21,7 @@
 #include "llvm/Target/TargetRegistry.h"
 using namespace llvm;
 
-static const MCAsmInfo *createMCAsmInfo(const Target &T,
-                                        const StringRef &TT) {
+static const MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
   Triple TheTriple(TT);
   switch (TheTriple.getOS()) {
   case Triple::Darwin:
diff --git a/lib/Target/PowerPC/PPCTargetMachine.cpp b/lib/Target/PowerPC/PPCTargetMachine.cpp
index 3371954..8079c6e 100644
--- a/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -20,8 +20,7 @@
 #include "llvm/Support/FormattedStream.h"
 using namespace llvm;
 
-static const MCAsmInfo *createMCAsmInfo(const Target &T,
-                                                const StringRef &TT) {
+static const MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
   Triple TheTriple(TT);
   bool isPPC64 = TheTriple.getArch() == Triple::ppc64;
   if (TheTriple.getOS() == Triple::Darwin)
diff --git a/lib/Target/TargetLoweringObjectFile.cpp b/lib/Target/TargetLoweringObjectFile.cpp
index c1aab99..3e17058 100644
--- a/lib/Target/TargetLoweringObjectFile.cpp
+++ b/lib/Target/TargetLoweringObjectFile.cpp
@@ -671,7 +671,7 @@
 
 
 const MCSectionMachO *TargetLoweringObjectFileMachO::
-getMachOSection(const StringRef &Segment, const StringRef &Section,
+getMachOSection(StringRef Segment, StringRef Section,
                 unsigned TypeAndAttributes,
                 unsigned Reserved2, SectionKind Kind) const {
   // We unique sections by their segment/section pair.  The returned section
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index a61de1c..5d58a87 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -22,8 +22,7 @@
 #include "llvm/Target/TargetRegistry.h"
 using namespace llvm;
 
-static const MCAsmInfo *createMCAsmInfo(const Target &T,
-                                                const StringRef &TT) {
+static const MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
   Triple TheTriple(TT);
   switch (TheTriple.getOS()) {
   case Triple::Darwin: