memory: Make regex patterns raw

According to the docs of `g_regex_new`: "Usually strings must be valid
UTF-8 strings, using this flag they are considered as a raw sequence
of bytes."

The "strings" this refers to are the haystacks we then pass to
`g_regex_match_full` when searching.

Without the flag, memory search with regex patterns can get
interrupted before the range is over, when "invalid" bytes are
encountered, resulting in false negatives.

gum/gummemory.c

@@ -576,7 +576,7 @@ gum_match_pattern_new_from_regex (const gchar * regex_str)
   GumMatchPattern * pattern;
   GRegex * regex;
 
-  regex = g_regex_new (regex_str, G_REGEX_OPTIMIZE, G_REGEX_MATCH_NOTEMPTY,
+  regex = g_regex_new (regex_str, G_REGEX_OPTIMIZE | G_REGEX_RAW, G_REGEX_MATCH_NOTEMPTY,
       NULL);
   if (regex == NULL)
     return NULL;