Spell `necessary' correctly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7944 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86CodeEmitter.cpp b/lib/Target/X86/X86CodeEmitter.cpp
index 5f19edb..9b9d06c 100644
--- a/lib/Target/X86/X86CodeEmitter.cpp
+++ b/lib/Target/X86/X86CodeEmitter.cpp
@@ -449,7 +449,7 @@
   unsigned Opcode = MI.getOpcode();
   const TargetInstrDescriptor &Desc = II->get(Opcode);
 
-  // Emit instruction prefixes if neccesary
+  // Emit instruction prefixes if necessary
   if (Desc.TSFlags & X86II::OpSize) MCE.emitByte(0x66);// Operand size...
 
   switch (Desc.TSFlags & X86II::Op0Mask) {