Use uname() for getparm for ARCH/MACH queries.

Previously, this was implemented in very inconsistent ways and
not yet implemented for most of the platforms that we're supporting
today.

The values for DOS are maintained as they were.

src/uutils.c

@@ -26,6 +26,7 @@
 
 #ifndef DOS
 #include <pwd.h>
+#include <sys/utsname.h>
 #endif
 
 #include "lispemul.h"
@@ -212,47 +213,36 @@ LispPTR unix_username(LispPTR *args) {
 /*									*/
 /************************************************************************/
 /*
- * The code for "MACH" and "ARCH" are really not correct and it's not
- * clear what use they are. RS/6000 systems use a PowerPC processor,
- * and so did PowerBook Macintosh systems.
- * "MACH" and "ARCH" both seem to be a mix of instruction set architecture and
- * system types (rs/6000 used PowerPC).
- * The only usage seems to be checking "ARCH" == "dos" and for the existance
- * of *any* result from the call, which indicates it's an emulated system.
+ * The only usage for "ARCH" seems to be checking "ARCH" == "dos"
+ * and for the existence of *any* result from the call, which
+ * indicates it's an emulated system.
  */
 char *getenv(const char *);
 
 LispPTR unix_getparm(LispPTR *args) {
   char envname[20], result[128], *envvalue;
+#ifndef DOS
+  struct utsname u;
+#endif
+
   if (lisp_string_to_c_string(args[0], envname, sizeof envname)) return NIL;
 
+#ifdef DOS
   if (strcmp(envname, "MACH") == 0) {
-#if defined(sparc)
-    envvalue = "sparc";
-#elif defined(I386)
-    envvalue = "i386";
-#elif defined(DOS)
     envvalue = "386";
-#elif defined(MACOSX)
-    envvalue = "i386";
-#else
-    envvalue = "mc68020";
-#endif
-
   } else if (strcmp(envname, "ARCH") == 0) {
-#if defined(sparc)
-    envvalue = "sun4";
-#elif defined(I386)
-    envvalue = "sun386";
-#elif defined(DOS)
     envvalue = "dos";
-#elif defined(MACOSX)
-    envvalue = "i386";
+  }
 #else
-    envvalue = "sun3";
-#endif
+  if (uname(&u) == -1) return NIL;
 
-  } else if (strcmp(envname, "DISPLAY") == 0) {
+  if (strcmp(envname, "MACH") == 0) {
+    envvalue = u.machine;
+  } else if (strcmp(envname, "ARCH") == 0) {
+    envvalue = u.sysname;
+  }
+#endif
+  else if (strcmp(envname, "DISPLAY") == 0) {
 #if defined(XWINDOW)
     envvalue = "X";
 #elif defined(DISPLAYBUFFER)