curl_ctype: convert to macros-only

This no longer provide functions, only macros. Runs faster and produces
smaller output.

The biggest precaution this change brings:

DO NOT use post/pre-increments when passing arguments to the macros.

Closes #9429

src/Makefile.inc

@@ -36,7 +36,6 @@ CURLX_CFILES = \
   ../lib/timediff.c \
   ../lib/nonblock.c \
   ../lib/warnless.c \
-  ../lib/curl_ctype.c \
   ../lib/curl_multibyte.c \
   ../lib/version_win32.c \
   ../lib/dynbuf.c

src/tool_formparse.c

@@ -499,7 +499,7 @@ static int get_param_part(struct OperationConfig *config, char endchar,
   sep = *p;
   *endpos = '\0';
   while(sep == ';') {
-    while(ISSPACE(*++p))
+    while(p++ && ISSPACE(*p))
       ;
 
     if(!endct && checkprefix("type=", p)) {