fix(runtime): do not allow breakcheck inside runtime path calculation

problem: breakcheck might run arbitrary lua code, which might require
modules and thus invoke runtime path calculation recursively.
solution: Block the use of breakcheck when expanding glob patterns
inside 'runtimepath'

fixes #23012

src/nvim/regexp.h

@@ -10,6 +10,7 @@
 #define RE_STRING       2       ///< match in string instead of buffer text
 #define RE_STRICT       4       ///< don't allow [abc] without ]
 #define RE_AUTO         8       ///< automatic engine selection
+#define RE_NOBREAK      16      ///< don't use breakcheck functions
 
 // values for reg_do_extmatch
 #define REX_SET        1       ///< to allow \z\(...\),