x86emul: fold local variables

Declare some variables to they can be used by multiple pieces of code,
allowing some figure braces to be dropped (which don't align nicely
when used inside of case labeled statements).

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -3561,6 +3561,8 @@ x86_emulate(
     case 0xf6 ... 0xf7: /* Grp3 */
         switch ( modrm_reg & 7 )
         {
+            unsigned long u[2], v;
+
         case 0 ... 1: /* test */
             goto test;
         case 2: /* not */
@@ -3599,15 +3601,15 @@ x86_emulate(
                 _regs.edx = (uint32_t)(dst.val >> 32);
                 break;
 #endif
-            default: {
-                unsigned long m[2] = { src.val, dst.val };
-                if ( mul_dbl(m) )
+            default:
+                u[0] = src.val;
+                u[1] = dst.val;
+                if ( mul_dbl(u) )
                     _regs.eflags |= EFLG_OF|EFLG_CF;
-                _regs.edx = m[1];
-                dst.val  = m[0];
+                _regs.edx = u[1];
+                dst.val  = u[0];
                 break;
             }
-            }
             break;
         case 5: /* imul */
             dst.type = OP_REG;
@@ -3643,20 +3645,18 @@ x86_emulate(
                     _regs.edx = (uint32_t)(dst.val >> 32);
                 break;
 #endif
-            default: {
-                unsigned long m[2] = { src.val, dst.val };
-                if ( imul_dbl(m) )
+            default:
+                u[0] = src.val;
+                u[1] = dst.val;
+                if ( imul_dbl(u) )
                     _regs.eflags |= EFLG_OF|EFLG_CF;
                 if ( b > 0x6b )
-                    _regs.edx = m[1];
-                dst.val  = m[0];
+                    _regs.edx = u[1];
+                dst.val  = u[0];
                 break;
             }
-            }
             break;
-        case 6: /* div */ {
-            unsigned long u[2], v;
-
+        case 6: /* div */
             dst.type = OP_REG;
             dst.reg  = (unsigned long *)&_regs.eax;
             switch ( dst.bytes = src.bytes )
@@ -3703,10 +3703,7 @@ x86_emulate(
                 break;
             }
             break;
-        }
-        case 7: /* idiv */ {
-            unsigned long u[2], v;
-
+        case 7: /* idiv */
             dst.type = OP_REG;
             dst.reg  = (unsigned long *)&_regs.eax;
             switch ( dst.bytes = src.bytes )
@@ -3754,7 +3751,6 @@ x86_emulate(
             }
             break;
         }
-        }
         break;
 
     case 0xf8: /* clc */