Replace "fallthrough" comments with LLVM_FALLTHROUGH

This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.

llvm-svn: 278902
diff --git a/llvm/lib/Target/ARM/ARMFastISel.cpp b/llvm/lib/Target/ARM/ARMFastISel.cpp
index 816d7b7b..960b711 100644
--- a/llvm/lib/Target/ARM/ARMFastISel.cpp
+++ b/llvm/lib/Target/ARM/ARMFastISel.cpp
@@ -1075,7 +1075,8 @@
                               TII.get(Opc), Res)
                       .addReg(SrcReg).addImm(1));
       SrcReg = Res;
-    } // Fallthrough here.
+      LLVM_FALLTHROUGH;
+    }
     case MVT::i8:
       if (isThumb2) {
         if (Addr.Offset < 0 && Addr.Offset > -256 && Subtarget->hasV6T2Ops())
@@ -1848,7 +1849,7 @@
       // For AAPCS ABI targets, just use VFP variant of the calling convention.
       return (Return ? RetCC_ARM_AAPCS_VFP : CC_ARM_AAPCS_VFP);
     }
-    // Fallthrough
+    LLVM_FALLTHROUGH;
   case CallingConv::C:
   case CallingConv::CXX_FAST_TLS:
     // Use target triple & subtarget features to do actual dispatch.