ARM NEON relax parse time diagnostics for alignment specifiers.

There's more variation that we need to handle. Error checking will need
to be on operand predicates.

llvm-svn: 146884
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
index c38a882..854729f 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
@@ -1372,11 +1372,11 @@
 
   switch (Imm.getImm()) {
   default: break;
-  case 2:
-  case 4:
   case 8:
-  case 16: Align = 0x00; break;
-  case 32: Align = 0x03; break;
+  case 16:
+  case 32: // Default '0' value for invalid alignments of 8, 16, 32 bytes.
+  case 2: Align = 0x00; break;
+  case 4: Align = 0x03; break;
   }
 
   return RegNo | (Align << 4);