panics: use the new facilities of testing.B instead

Lots of panics go away.
Also fix a name error in html/template.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5498045
diff --git a/src/pkg/regexp/all_test.go b/src/pkg/regexp/all_test.go
index 8810796..e729510 100644
--- a/src/pkg/regexp/all_test.go
+++ b/src/pkg/regexp/all_test.go
@@ -324,8 +324,7 @@
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		if !re.MatchString(x) {
-			println("no match!")
-			break
+			b.Fatalf("no match!")
 		}
 	}
 }
@@ -337,8 +336,7 @@
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		if !re.MatchString(x) {
-			println("no match!")
-			break
+			b.Fatalf("no match!")
 		}
 	}
 }
@@ -350,8 +348,7 @@
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		if !re.MatchString(x) {
-			println("no match!")
-			break
+			b.Fatalf("no match!")
 		}
 	}
 }
@@ -365,8 +362,7 @@
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		if !re.MatchString(x) {
-			println("no match!")
-			break
+			b.Fatalf("no match!")
 		}
 	}
 }