Replace a few more "fall through" comments with LLVM_FALLTHROUGH

Follow up to r278902. I had missed "fall through", with a space.

llvm-svn: 278970
diff --git a/llvm/lib/Target/X86/X86FastISel.cpp b/llvm/lib/Target/X86/X86FastISel.cpp
index ada3d99..f30331f 100644
--- a/llvm/lib/Target/X86/X86FastISel.cpp
+++ b/llvm/lib/Target/X86/X86FastISel.cpp
@@ -2969,7 +2969,7 @@
     default: llvm_unreachable("Unexpected value type.");
     case MVT::i32: SrcReg = GPR32ArgRegs[GPRIdx++]; break;
     case MVT::i64: SrcReg = GPR64ArgRegs[GPRIdx++]; break;
-    case MVT::f32: // fall-through
+    case MVT::f32: LLVM_FALLTHROUGH;
     case MVT::f64: SrcReg = XMMArgRegs[FPRIdx++]; break;
     }
     unsigned DstReg = FuncInfo.MF->addLiveIn(SrcReg, RC);
@@ -3508,7 +3508,7 @@
   unsigned Opc = 0;
   switch (VT.SimpleTy) {
   default: llvm_unreachable("Unexpected value type");
-  case MVT::i1:  VT = MVT::i8; // fall-through
+  case MVT::i1:  VT = MVT::i8;       LLVM_FALLTHROUGH;
   case MVT::i8:  Opc = X86::MOV8ri;  break;
   case MVT::i16: Opc = X86::MOV16ri; break;
   case MVT::i32: Opc = X86::MOV32ri; break;