cmd/compile: regenerate knownFormats

Should fix the build dashboard.

Change-Id: Id4c8a996d9f689e1fa865a9cff9a7f52c700c691
Reviewed-on: https://go-review.googlesource.com/37877
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/compile/fmt_test.go

@@ -656,6 +656,7 @@ var knownFormats = map[string]string{
 	"cmd/compile/internal/syntax.token %s":            "",
 	"cmd/internal/obj.As %v":                          "",
 	"cmd/internal/src.Pos %s":                         "",
+	"cmd/internal/src.Pos %v":                         "",
 	"error %v":                                        "",
 	"float64 %.2f":                                    "",
 	"float64 %.3f":                                    "",