kernel: remove MakeImmutableString

This was simply an alias for MakeImmutableNoRecurse, and calling
it was a very minor (mostly: pointless) optimization compared to
calling the more generic MakeImmutable.

But crucially, the name was rather misleading, in particular when
compared to MakeImmString.

So, let's avoid some potential confusion (and the resulting source
of bugs) with a teeny weeny de-optimization (that won't even be
noticeable in practice).

src/code.c

@@ -192,7 +192,7 @@ Obj GET_FILENAME_BODY(Obj body)
 void SET_FILENAME_BODY(Obj body, Obj val)
 {
     GAP_ASSERT(IS_STRING_REP(val));
-    MakeImmutableString(val);
+    MakeImmutable(val);
     BODY_HEADER(body)->filename_or_id = val;
 }
 
@@ -220,7 +220,7 @@ Obj GET_LOCATION_BODY(Obj body)
 void SET_LOCATION_BODY(Obj body, Obj val)
 {
     GAP_ASSERT(IS_STRING_REP(val));
-    MakeImmutableString(val);
+    MakeImmutable(val);
     BODY_HEADER(body)->startline_or_location = val;
 }
 

src/gvars.c

@@ -394,7 +394,7 @@ void AssGVarWithoutReadOnlyCheck(UInt gvar, Obj val)
 #endif
     if ( val != 0 && TNUM_OBJ(val) == T_FUNCTION && NAME_FUNC(val) == 0 ) {
         onam = CopyToStringRep(NameGVar(gvar));
-        MakeImmutableString(onam);
+        MakeImmutable(onam);
         SET_NAME_FUNC(val, onam);
         CHANGED_BAG(val);
     }

src/hpc/thread.c

@@ -302,7 +302,7 @@ static Obj MakeImmString2(const Char * cstr1, const Char * cstr2)
     result = NEW_STRING(len1 + len2);
     memcpy(CSTR_STRING(result), cstr1, len1);
     memcpy(CSTR_STRING(result) + len1, cstr2, len2);
-    MakeImmutableString(result);
+    MakeImmutableNoRecurse(result);
     return result;
 }
 

src/opers.c

@@ -2605,7 +2605,7 @@ static Obj WRAP_NAME(Obj name, const char *addon)
     ptr += name_len;
     *ptr++ = ')';
     *ptr = 0;
-    MakeImmutableString(fname);
+    MakeImmutable(fname);
     return fname;
 }
 
@@ -2622,7 +2622,7 @@ static Obj PREFIX_NAME(Obj name, const char *prefix)
     memcpy( ptr, CONST_CSTR_STRING(name), name_len );
     ptr += name_len;
     *ptr = 0;
-    MakeImmutableString(fname);
+    MakeImmutable(fname);
     return fname;
 }
 

src/stringobj.c

@@ -1197,7 +1197,7 @@ Obj ImmutableString(Obj string)
 {
     if (!IS_STRING_REP(string) || IS_MUTABLE_OBJ(string)) {
         string = CopyToStringRep(string);
-        MakeImmutableString(string);
+        MakeImmutableNoRecurse(string);
     }
     return string;
 }
@@ -2116,9 +2116,9 @@ static Int InitKernel (
            UnbListFuncs    [ t1            ] = UnbString;
     }
 
-    MakeImmutableObjFuncs[ T_STRING       ] = MakeImmutableString;
-    MakeImmutableObjFuncs[ T_STRING_SSORT ] = MakeImmutableString;
-    MakeImmutableObjFuncs[ T_STRING_NSORT ] = MakeImmutableString;
+    MakeImmutableObjFuncs[ T_STRING       ] = MakeImmutableNoRecurse;
+    MakeImmutableObjFuncs[ T_STRING_SSORT ] = MakeImmutableNoRecurse;
+    MakeImmutableObjFuncs[ T_STRING_NSORT ] = MakeImmutableNoRecurse;
 
     /* return success                                                      */
     return 0;

src/stringobj.h

@@ -325,16 +325,6 @@ void ConvString(Obj string);
 Int IsStringConv(Obj obj);
 
 
-/****************************************************************************
-**
-*F  MakeImmutableString( <str> ) . . . . . . make a string immutable in place
-*/
-EXPORT_INLINE void MakeImmutableString(Obj str)
-{
-    MakeImmutableNoRecurse(str);
-}
-
-
 // Functions to create mutable and immutable GAP strings from C strings.
 // MakeString and MakeImmString are inlineable so 'strlen' can be optimised
 // away for constant strings.
@@ -354,14 +344,14 @@ EXPORT_INLINE Obj MakeString(const char * cstr)
 EXPORT_INLINE Obj MakeImmString(const char * cstr)
 {
     Obj result = MakeString(cstr);
-    MakeImmutableString(result);
+    MakeImmutableNoRecurse(result);
     return result;
 }
 
 EXPORT_INLINE Obj MakeImmStringWithLen(const char * buf, size_t len)
 {
     Obj result = MakeStringWithLen(buf, len);
-    MakeImmutableString(result);
+    MakeImmutableNoRecurse(result);
     return result;
 }