diff --git a/lib/Target/ARM/AsmParser/x b/lib/Target/ARM/AsmParser/x
deleted file mode 100644
index 1496e70647d..00000000000
--- a/lib/Target/ARM/AsmParser/x
+++ /dev/null
@@ -1,23 +0,0 @@
-diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
-index af973e8..cbdae2a 100644
---- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
-+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
-@@ -3254,7 +3254,8 @@ parseMSRMaskOperand(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
-   SMLoc S = Parser.getTok().getLoc();
-   const AsmToken &Tok = Parser.getTok();
-   assert(Tok.is(AsmToken::Identifier) && "Token is not an Identifier");
--  StringRef Mask = Tok.getString();
-+  std::string MaskStr = Tok.getString().lower();
-+  StringRef Mask = MaskStr; // convenience for slice() and such.
- 
-   if (isMClass()) {
-     // See ARMv6-M 10.1.1
-@@ -3290,7 +3291,7 @@ parseMSRMaskOperand(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
-   // Split spec_reg from flag, example: CPSR_sxf => "CPSR" and "sxf"
-   size_t Start = 0, Next = Mask.find('_');
-   StringRef Flags = "";
--  std::string SpecReg = Mask.slice(Start, Next).lower();
-+  StringRef SpecReg = Mask.slice(Start, Next);
-   if (Next != StringRef::npos)
-     Flags = Mask.slice(Next+1, Mask.size());
-