Fix compilation with Open Watcom

Open Watcom does not support 64-bit constants at 'case'.

[ hpa: I'm pulling this, but I'm really, *really* questioning its
supportability long term. The OpenWatcom people need to fix this, or
we are just going to have to say "OW is not supported."

At some point we *are* going to move to a "C99 is baseline" policy for
code; there are simply too many features in C99 that are actively
painful to be without.

That is, unless we decide to go to C++, which is under consideration
but is a much bigger job. In that case, the target will probably be
either C++11 or C++14 as those C++ versions contain some pretty
essential features. ]

Signed-off-by: KO Myung-Hun <komh78@gmail.com>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>

asm/assemble.c

@@ -3103,6 +3103,7 @@ static enum match_result matches(const struct itemplate * const itemp,
              * If this is an *explicitly* sized immediate,
              * allow it to match an extending pattern.
              */
+#ifndef __WATCOMC__
             switch (isize[i]) {
             case BITS8:
                 if (ttype & BYTEEXTMASK) {
@@ -3117,6 +3118,18 @@ static enum match_result matches(const struct itemplate * const itemp,
             default:
                 break;
             }
+#else
+            /* Open Watcom does not support 64-bit constants at *case*. */
+            if (isize[i] == BITS8) {
+                if (ttype & BYTEEXTMASK) {
+                    isize[i]  = tsize[i];
+                    itype[i] |= BYTEEXTMASK;
+                }
+            } else if (isize[i] == BITS32) {
+                if (ttype & DWORDEXTMASK)
+                    isize[i]  = tsize[i];
+            }
+#endif
 
             /*
              * MOST instructions which take an sdword64 are the only form;

disasm/disasm.c

@@ -113,6 +113,7 @@ static enum reg_enum whichreg(opflags_t regflags, int regval, uint32_t rex)
  */
 static enum reg_enum implicit_reg(opflags_t regflags)
 {
+#ifndef __WATCOMC__
     switch (regflags) {
     case REG_AL:  return R_AL;
     case REG_AX:  return R_AX;
@@ -139,6 +140,56 @@ static enum reg_enum implicit_reg(opflags_t regflags)
     case OPMASK0: return R_K0;
     default:      return 0;
     }
+#else
+    /* Open Watcom does not support 64-bit constants at *case*. */
+    if (regflags == REG_AL)
+        return R_AL;
+    if (regflags == REG_AX)
+        return R_AX;
+    if (regflags == REG_EAX)
+        return R_EAX;
+    if (regflags == REG_RAX)
+        return R_RAX;
+    if (regflags == REG_DL)
+        return R_DL;
+    if (regflags == REG_DX)
+        return R_DX;
+    if (regflags == REG_EDX)
+        return R_EDX;
+    if (regflags == REG_RDX)
+        return R_RDX;
+    if (regflags == REG_CL)
+        return R_CL;
+    if (regflags == REG_CX)
+        return R_CX;
+    if (regflags == REG_ECX)
+        return R_ECX;
+    if (regflags == REG_RCX)
+        return R_RCX;
+    if (regflags == FPU0)
+        return R_ST0;
+    if (regflags == XMM0)
+        return R_XMM0;
+    if (regflags == YMM0)
+        return R_YMM0;
+    if (regflags == ZMM0)
+        return R_ZMM0;
+    if (regflags == REG_ES)
+        return R_ES;
+    if (regflags == REG_CS)
+        return R_CS;
+    if (regflags == REG_SS)
+        return R_SS;
+    if (regflags == REG_DS)
+        return R_DS;
+    if (regflags == REG_FS)
+        return R_FS;
+    if (regflags == REG_GS)
+        return R_GS;
+    if (regflags == OPMASK0)
+        return R_K0;
+    return 0;
+#endif
 }
 
 /*