Support printing Regular_Expression in fmt

core/fmt/fmt.odin

@@ -9,6 +9,7 @@ import "core:io"
 import "core:reflect"
 import "core:strconv"
 import "core:strings"
+import "core:text/regex"
 import "core:time"
 import "core:unicode/utf8"
 
@@ -2405,6 +2406,21 @@ fmt_named :: proc(fi: ^Info, v: any, verb: rune, info: runtime.Type_Info_Named)
 			write_padded_number(fi, (ns), 9)
 			io.write_string(fi.writer, " +0000 UTC", &fi.n)
 			return
+
+		case regex.Regular_Expression:
+			io.write_byte(fi.writer, '/')
+			for r in a.original_pattern {
+				if r == '/' {
+					io.write_string(fi.writer, `\/`)
+				} else {
+					io.write_rune(fi.writer, r)
+				}
+			}
+			io.write_byte(fi.writer, '/')
+			for flag in a.flags {
+				io.write_byte(fi.writer, regex.Flag_To_Letter[flag])
+			}
+			return
 		}
 	}