ALL: Massive 'const' cleanup

These changes facilitate more robust parameter type checking and helps
to identify unexpected coding errors.

Most simulators can now also be compiled with a C++ compiler without
warnings.

Additionally, these changes have also been configured to facilitate easier
backporting of simulator and device simulation modules to run under the
simh v3.9+ SCP framework.

Author: markpizz

ALTAIR/altair_cpu.c

@@ -113,7 +113,7 @@ int32 PCX;                                              /* External view of PC *
 t_stat cpu_ex (t_value *vptr, t_addr addr, UNIT *uptr, int32 sw);
 t_stat cpu_dep (t_value val, t_addr addr, UNIT *uptr, int32 sw);
 t_stat cpu_reset (DEVICE *dptr);
-t_stat cpu_set_size (UNIT *uptr, int32 val, char *cptr, void *desc);
+t_stat cpu_set_size (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
 void setarith(int32 reg);
 void setlogical(int32 reg);
 void setinc(int32 reg);
@@ -1163,7 +1163,7 @@ t_stat cpu_dep (t_value val, t_addr addr, UNIT *uptr, int32 sw)
     return SCPE_OK;
 }
 
-t_stat cpu_set_size (UNIT *uptr, int32 val, char *cptr, void *desc)
+t_stat cpu_set_size (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
 {
 int32 mc = 0;
 uint32 i;

ALTAIR/altair_sys.c

@@ -153,7 +153,7 @@ int32 oplen[256] = {
    load starts at the current value of the PC.
 */
 
-t_stat sim_load (FILE *fileref, char *cptr, char *fnam, int flag)
+t_stat sim_load (FILE *fileref, CONST char *cptr, CONST char *fnam, int flag)
 {
 int32 i, addr = 0, cnt = 0;
 
@@ -234,7 +234,7 @@ return -(oplen[inst] - 1);
         status  =       error status
 */
 
-t_stat parse_sym (char *cptr, t_addr addr, UNIT *uptr, t_value *val, int32 sw)
+t_stat parse_sym (CONST char *cptr, t_addr addr, UNIT *uptr, t_value *val, int32 sw)
 {
 int32 cflag, i = 0, j, r;
 char gbuf[CBUFSIZE];