Alphabetize forward declarations

llvm-svn: 211509
diff --git a/llvm/lib/Target/R600/AMDGPUMCInstLower.h b/llvm/lib/Target/R600/AMDGPUMCInstLower.h
index 2b7f1e3..58fe34d 100644
--- a/llvm/lib/Target/R600/AMDGPUMCInstLower.h
+++ b/llvm/lib/Target/R600/AMDGPUMCInstLower.h
@@ -14,9 +14,9 @@
 namespace llvm {
 
 class AMDGPUSubtarget;
-class MCInst;
-class MCContext;
 class MachineInstr;
+class MCContext;
+class MCInst;
 
 class AMDGPUMCInstLower {