basic : Make NeedEsc easier to read

Change-Id: Ie2ee404a51262cd08673268169a41255abf012bd
Reviewed-on: https://gerrit.libreoffice.org/31600Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

basic/source/runtime/runtime.cxx

@@ -1400,11 +1400,11 @@ namespace
 {
     bool NeedEsc(sal_Unicode cCode)
     {
-        if((cCode & 0xFF80))
+        if(!rtl::isAscii(cCode))
         {
             return false;
         }
-        switch((sal_uInt8)(cCode & 0x07F))
+        switch(cCode)
         {
         case '.':
         case '^':