AArch64: remove extraneous padding

The structs BarrierOp, PrefetchOp, PSBHintOp are in AArch64AsmParser.cpp
(inside anonymous namespace).  This diff changes the order of fields and
removes the excessive padding (8 bytes).

Patch by Alexander Shaposhnikov!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279173 91177308-0d34-0410-b5e6-96231b3b80d8

Author: compnerd

lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -208,9 +208,9 @@ class AArch64Operand : public MCParsedAsmOperand {
   };
 
   struct BarrierOp {
-    unsigned Val; // Not the enum since not all values have names.
     const char *Data;
     unsigned Length;
+    unsigned Val; // Not the enum since not all values have names.
   };
 
   struct SysRegOp {
@@ -226,15 +226,15 @@ class AArch64Operand : public MCParsedAsmOperand {
   };
 
   struct PrefetchOp {
-    unsigned Val;
     const char *Data;
     unsigned Length;
+    unsigned Val;
   };
 
   struct PSBHintOp {
-    unsigned Val;
     const char *Data;
     unsigned Length;
+    unsigned Val;
   };
 
   struct ShiftExtendOp {