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
diff --git a/rust/rust_test.go b/rust/rust_test.go
index 4842a4c..26e943a 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -135,6 +135,7 @@
 
 // Test that we can extract the link path from a lib path.
 func TestLinkPathFromFilePath(t *testing.T) {
+	t.Parallel()
 	barPath := android.PathForTesting("out/soong/.intermediates/external/libbar/libbar/linux_glibc_x86_64_shared/libbar.so")
 	libName := linkPathFromFilePath(barPath)
 	expectedResult := "out/soong/.intermediates/external/libbar/libbar/linux_glibc_x86_64_shared/"
@@ -146,6 +147,7 @@
 
 // Test to make sure dependencies are being picked up correctly.
 func TestDepsTracking(t *testing.T) {
+	t.Parallel()
 	ctx := testRust(t, `
 		rust_ffi_host_static {
 			name: "libstatic",
@@ -207,6 +209,7 @@
 }
 
 func TestSourceProviderDeps(t *testing.T) {
+	t.Parallel()
 	ctx := testRust(t, `
 		rust_binary {
 			name: "fizz-buzz-dep",
@@ -294,6 +297,7 @@
 }
 
 func TestSourceProviderTargetMismatch(t *testing.T) {
+	t.Parallel()
 	// This might error while building the dependency tree or when calling depsToPaths() depending on the lunched
 	// target, which results in two different errors. So don't check the error, just confirm there is one.
 	testRustError(t, ".*", `
@@ -316,6 +320,7 @@
 
 // Test to make sure proc_macros use host variants when building device modules.
 func TestProcMacroDeviceDeps(t *testing.T) {
+	t.Parallel()
 	ctx := testRust(t, `
 		rust_library_host_rlib {
 			name: "libbar",
@@ -343,6 +348,7 @@
 
 // Test that no_stdlibs suppresses dependencies on rust standard libraries
 func TestNoStdlibs(t *testing.T) {
+	t.Parallel()
 	ctx := testRust(t, `
 		rust_binary {
 			name: "fizz-buzz",
@@ -358,6 +364,7 @@
 
 // Test that libraries provide both 32-bit and 64-bit variants.
 func TestMultilib(t *testing.T) {
+	t.Parallel()
 	ctx := testRust(t, `
 		rust_library_rlib {
 			name: "libfoo",