fix #12122 (#21096)

lib/std/envvars.nim

@@ -183,7 +183,7 @@ when not defined(nimscript):
               let kv = $e
               let p = find(kv, '=')
               yield (substr(kv, 0, p-1), substr(kv, p+1))
-              e = cast[typ](cast[ByteAddress](eend)+size)
+              e = cast[typ](cast[int](eend)+size)
               if typeof(zero)(eend[1]) == zero: break
             discard free_fun(env)
           impl(getEnvironmentStringsW, WideCString, 2, 0, freeEnvironmentStringsW)

lib/std/private/strimpl.nim

@@ -93,7 +93,7 @@ func find*(s: cstring, sub: char, start: Natural = 0, last = 0): int =
   if L > 0:
     let found = c_memchr(s[start].unsafeAddr, sub, cast[csize_t](L))
     if not found.isNil:
-      return cast[ByteAddress](found) -% cast[ByteAddress](s)
+      return cast[int](found) -% cast[int](s)
   return -1
 
 func find*(s, sub: cstring, start: Natural = 0, last = 0): int =
@@ -108,6 +108,6 @@ func find*(s, sub: cstring, start: Natural = 0, last = 0): int =
   if last == 0 and s.len > start:
     let found = c_strstr(cast[cstring](s[start].unsafeAddr), sub)
     if not found.isNil:
-      result = cast[ByteAddress](found) -% cast[ByteAddress](s)
+      result = cast[int](found) -% cast[int](s)
     else:
       result = -1

lib/std/syncio.nim

@@ -480,7 +480,7 @@ proc readLine*(f: File, line: var string): bool {.tags: [ReadIOEffect],
     let m = c_memchr(addr line[pos], '\L'.ord, cast[csize_t](sp))
     if m != nil:
       # \l found: Could be our own or the one by fgets, in any case, we're done
-      var last = cast[ByteAddress](m) - cast[ByteAddress](addr line[0])
+      var last = cast[int](m) - cast[int](addr line[0])
       if last > 0 and line[last-1] == '\c':
         line.setLen(last-1)
         return last > 1 or fgetsSuccess