objc: use compile-time macOS version checks

Use "modern" APIs for calling inherited messages when targeting Mac OS X 10.6
or later

compiler/ncal.pas

@@ -2764,10 +2764,10 @@ implementation
           begin
             if not(cnf_inherited in callnodeflags) then
               msgsendname:='OBJC_MSGSEND_STRET'
-{$if defined(onlymacosx10_6) or defined(arm) }
-            else if (target_info.system in systems_objc_nfabi) then
+            else if (target_info.system in systems_objc_nfabi) and
+                    (not MacOSXVersionMin.isvalid or
+                     (MacOSXVersionMin.relationto(10,6,0)>=0)) then
               msgsendname:='OBJC_MSGSENDSUPER2_STRET'
-{$endif onlymacosx10_6 or arm}
             else
               msgsendname:='OBJC_MSGSENDSUPER_STRET'
           end
@@ -2781,12 +2781,12 @@ implementation
         { default }
         else
 {$endif aarch64}
-             if not(cnf_inherited in callnodeflags) then
-          msgsendname:='OBJC_MSGSEND'
-{$if defined(onlymacosx10_6) or defined(arm) or defined(aarch64)}
-        else if (target_info.system in systems_objc_nfabi) then
+          if not(cnf_inherited in callnodeflags) then
+            msgsendname:='OBJC_MSGSEND'
+        else if (target_info.system in systems_objc_nfabi) and
+                (not MacOSXVersionMin.isvalid or
+                 (MacOSXVersionMin.relationto(10,6,0)>=0)) then
           msgsendname:='OBJC_MSGSENDSUPER2'
-{$endif onlymacosx10_6 or arm}
         else
           msgsendname:='OBJC_MSGSENDSUPER';
 

compiler/objcutil.pas

@@ -52,7 +52,7 @@ interface
 implementation
 
     uses
-      globtype,
+      globtype,globals,versioncmp,
       cutils,
       pass_1,
       verbose,systems,
@@ -153,13 +153,13 @@ end;
                 { in case we are in a category method, we need the metaclass of the
                   superclass class extended by this category (= metaclass of superclass of superclass)
                   for the fragile abi, and the metaclass of the superclass for the non-fragile ABI }
-{$if defined(onlymacosx10_6) or defined(arm) or defined(aarch64)}
                 { NOTE: those send2 methods are only available on Mac OS X 10.6 and later!
                     (but also on all iPhone SDK revisions we support) }
-                if (target_info.system in systems_objc_nfabi) then
+                if (target_info.system in systems_objc_nfabi) and
+                   (not MacOSXVersionMin.isvalid or
+                    (MacOSXVersionMin.relationto(10,6,0)>=0)) then
                   result:=cloadvmtaddrnode.create(ctypenode.create(tobjectdef(tclassrefdef(def).pointeddef).childof))
                 else
-{$endif onlymacosx10_6 or arm aarch64}
                   result:=cloadvmtaddrnode.create(ctypenode.create(tobjectdef(tclassrefdef(def).pointeddef).childof.childof));
                 tloadvmtaddrnode(result).forcall:=true;
                 result:=cloadvmtaddrnode.create(result);
@@ -183,14 +183,14 @@ end;
             tloadvmtaddrnode(result).forcall:=true;
           end;
 
-{$if defined(onlymacosx10_6) or defined(arm) or defined(aarch64)}
         { For the non-fragile ABI, the superclass send2 method itself loads the
           superclass. For the fragile ABI, we have to do this ourselves.
 
           NOTE: those send2 methods are only available on Mac OS X 10.6 and later!
             (but also on all iPhone SDK revisions we support) }
-        if not(target_info.system in systems_objc_nfabi) then
-{$endif onlymacosx10_6 or arm or aarch64}
+        if not(target_info.system in systems_objc_nfabi) or
+           (MacOSXVersionMin.isvalid and
+            (MacOSXVersionMin.relationto(10,6,0)<0)) then
           result:=objcloadbasefield(result,'SUPERCLASS');
         typecheckpass(result);
       end;