fmt: %b for complex64 and complex128

Just an oversight they were missing.
Fixes #6387

R=golang-dev, dominik.honnef, rsc
CC=golang-dev
https://golang.org/cl/13715043

src/pkg/fmt/fmt_test.go

@@ -227,6 +227,8 @@ var fmtTests = []struct {
 	{"%+.3g", -1.0, "-1"},
 	{"% .3g", -1.0, "-1"},
 	{"% .3g", 1.0, " 1"},
+	{"%b", float32(1.0), "8388608p-23"},
+	{"%b", 1.0, "4503599627370496p-52"},
 
 	// complex values
 	{"%+.3e", 0i, "(+0.000e+00+0.000e+00i)"},
@@ -247,6 +249,8 @@ var fmtTests = []struct {
 	{"% .3E", -1 - 2i, "(-1.000E+00-2.000E+00i)"},
 	{"%+.3g", complex64(1 + 2i), "(+1+2i)"},
 	{"%+.3g", complex128(1 + 2i), "(+1+2i)"},
+	{"%b", complex64(1 + 2i), "(8388608p-23+8388608p-22i)"},
+	{"%b", 1 + 2i, "(4503599627370496p-52+4503599627370496p-51i)"},
 
 	// erroneous formats
 	{"", 2, "%!(EXTRA int=2)"},

src/pkg/fmt/format.go

@@ -429,6 +429,8 @@ func (f *fmt) fmt_c64(v complex64, verb rune) {
 	oldPlus := f.plus
 	for i := 0; ; i++ {
 		switch verb {
+		case 'b':
+			f.fmt_fb32(r)
 		case 'e':
 			f.fmt_e32(r)
 		case 'E':
@@ -457,6 +459,8 @@ func (f *fmt) fmt_c128(v complex128, verb rune) {
 	oldPlus := f.plus
 	for i := 0; ; i++ {
 		switch verb {
+		case 'b':
+			f.fmt_fb64(r)
 		case 'e':
 			f.fmt_e64(r)
 		case 'E':

src/pkg/fmt/print.go

@@ -511,7 +511,7 @@ func (p *pp) fmtFloat64(v float64, verb rune) {
 
 func (p *pp) fmtComplex64(v complex64, verb rune) {
 	switch verb {
-	case 'e', 'E', 'f', 'F', 'g', 'G':
+	case 'b', 'e', 'E', 'f', 'F', 'g', 'G':
 		p.fmt.fmt_c64(v, verb)
 	case 'v':
 		p.fmt.fmt_c64(v, 'g')
@@ -522,7 +522,7 @@ func (p *pp) fmtComplex64(v complex64, verb rune) {
 
 func (p *pp) fmtComplex128(v complex128, verb rune) {
 	switch verb {
-	case 'e', 'E', 'f', 'F', 'g', 'G':
+	case 'b', 'e', 'E', 'f', 'F', 'g', 'G':
 		p.fmt.fmt_c128(v, verb)
 	case 'v':
 		p.fmt.fmt_c128(v, 'g')