Make lots of tests run in parallel

Putting t.Parallel() in each test makes them run in parallel.
Additional t.Parallel() could be added to each subtest, although
that requires making a local copy of the loop variable for
table driven tests.

Test: m checkbuild
Change-Id: I5d9869ead441093f4d7c5757f2447385333a95a4

jar/jar_test.go

@@ -21,6 +21,7 @@ import (
 )
 
 func TestGetJavaPackage(t *testing.T) {
+	t.Parallel()
 	type args struct {
 		r   io.Reader
 		src string
@@ -78,6 +79,7 @@ func TestGetJavaPackage(t *testing.T) {
 }
 
 func Test_javaIdentRune(t *testing.T) {
+	t.Parallel()
 	// runes that should be valid anywhere in an identifier
 	validAnywhere := []rune{
 		// letters, $, _