12310 Add demangle(1) command

*** 19,28 ****
--- 19,29 ----
  #include <string.h>
  #include <errno.h>
  #include <pthread.h>
  #include <sys/ctype.h>
  #include <sys/debug.h>
+ #include <sys/sysmacros.h>
  #include <stdarg.h>
  #include "demangle-sys.h"
  #include "demangle_int.h"
  
  #define DEMANGLE_DEBUG  "DEMANGLE_DEBUG"
*** 29,51 ****
  
  static pthread_once_t debug_once = PTHREAD_ONCE_INIT;
  volatile boolean_t demangle_debug;
  FILE *debugf = stderr;
  
  static const char *
  langstr(sysdem_lang_t lang)
  {
!         switch (lang) {
!         case SYSDEM_LANG_AUTO:
!                 return ("auto");
!         case SYSDEM_LANG_CPP:
!                 return ("c++");
!         case SYSDEM_LANG_RUST:
!                 return ("rust");
!         default:
                  return ("invalid");
          }
  }
  
  static sysdem_lang_t
  detect_lang(const char *str, size_t n)
  {
--- 30,73 ----
  
  static pthread_once_t debug_once = PTHREAD_ONCE_INIT;
  volatile boolean_t demangle_debug;
  FILE *debugf = stderr;
  
+ static struct {
+         const char      *str;
+         sysdem_lang_t   lang;
+ } lang_tbl[] = {
+         { "auto", SYSDEM_LANG_AUTO },
+         { "c++", SYSDEM_LANG_CPP },
+         { "rust", SYSDEM_LANG_RUST },
+ };
+ 
  static const char *
  langstr(sysdem_lang_t lang)
  {
!         size_t i;
! 
!         for (i = 0; i < ARRAY_SIZE(lang_tbl); i++) {
!                 if (lang == lang_tbl[i].lang)
!                         return (lang_tbl[i].str);
!         }
          return ("invalid");
+ }
+ 
+ boolean_t
+ sysdem_parse_lang(const char *str, sysdem_lang_t *langp)
+ {
+         size_t i;
+ 
+         for (i = 0; i < ARRAY_SIZE(lang_tbl); i++) {
+                 if (strcmp(str, lang_tbl[i].str) == 0) {
+                         *langp = lang_tbl[i].lang;
+                         return (B_TRUE);
                  }
+         }
+ 
+         return (B_FALSE);
  }
  
  static sysdem_lang_t
  detect_lang(const char *str, size_t n)
  {