Fix arm specific failure in tw12048

git-svn-id: trunk@42657 -

rtl/inc/heaptrc.pp

@@ -562,7 +562,9 @@ begin
    pp^.extra_info:=nil;
   if add_tail then
     begin
-      pl:=pointer(pp)+allocsize-pp^.extra_info_size-tail_size;
+      { Calculate position from start because of arm
+        specific alignment }
+      pl:=pointer(pp)+sizeof(theap_mem_info)+pp^.size;
       for i:=1 to tail_size div sizeof(dword) do
         begin
           unaligned(pl^):=dword(AllocateSig);
@@ -924,7 +926,9 @@ begin
    pp^.extra_info:=nil;
   if add_tail then
     begin
-      pl:=pointer(pp)+allocsize-pp^.extra_info_size-tail_size;
+      { Calculate position from start because of arm
+        specific alignment }
+      pl:=pointer(pp)+sizeof(theap_mem_info)+pp^.size;
       for i:=1 to tail_size div sizeof(dword) do
         begin
           unaligned(pl^):=dword(AllocateSig);