regex: added rounded squares to backslash chars list, bug fix #7339 (#7346)

vlib/regex/regex.v

@@ -393,7 +393,7 @@ const(
 	]
 
 	// these chars are escape if preceded by a \
-	bsls_escape_list = [`\\`, `|`, `.`, `*`, `+`, `-`, `{`, `}`, `[`, `]`]
+	bsls_escape_list = [`\\`, `|`, `.`, `:`, `*`, `+`, `-`, `{`, `}`, `[`, `]`, `(`, `)`, `?`]
 )
 
 enum BSLS_parse_state {

vlib/regex/regex_test.v

@@ -119,6 +119,11 @@ match_test_suite = [
 	TestItem{"accccb deer", r"^a(.*)b d(.+)",0,11},
 	TestItem{"accccb deer", r"^(.*)$",0,11},
 	TestItem{"accccb deer", r"^a(.*)b d(.+)p",-1,0},
+
+	// test bcksls chars
+	TestItem{"[ an s. s! ]( wi4ki:something )", r"\[.*\]\( *(\w*:*\w+) *\)",0,31},
+	TestItem{"[ an s. s! ](wiki:something)", r"\[.*\]\( *(\w*:*\w+) *\)",0,28},
+	
 ]
 )