Pass Config to NewTestContext instead of ctx.Register

Prepare for using Config when adding singletons by passing
Config to NewTestContext and NewContext instead of to ctx.Register.
This will enable a followup change to store SingletonMakeVarsProviders
registered on the Context in the Config, which is necessary to run
multiple tests in parallel without data races.

Test: all soong tests
Change-Id: Id229629a4e42ff4487d317241673837726c075fc
diff --git a/android/paths_test.go b/android/paths_test.go
index e7fd763..14a4773 100644
--- a/android/paths_test.go
+++ b/android/paths_test.go
@@ -980,12 +980,6 @@
 func testPathForModuleSrc(t *testing.T, buildDir string, tests []pathForModuleSrcTestCase) {
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			ctx := NewTestContext()
-
-			ctx.RegisterModuleType("test", pathForModuleSrcTestModuleFactory)
-			ctx.RegisterModuleType("output_file_provider", pathForModuleSrcOutputFileProviderModuleFactory)
-			ctx.RegisterModuleType("filegroup", FileGroupFactory)
-
 			fgBp := `
 				filegroup {
 					name: "a",
@@ -1015,7 +1009,13 @@
 
 			config := TestConfig(buildDir, nil, "", mockFS)
 
-			ctx.Register(config)
+			ctx := NewTestContext(config)
+
+			ctx.RegisterModuleType("test", pathForModuleSrcTestModuleFactory)
+			ctx.RegisterModuleType("output_file_provider", pathForModuleSrcOutputFileProviderModuleFactory)
+			ctx.RegisterModuleType("filegroup", FileGroupFactory)
+
+			ctx.Register()
 			_, errs := ctx.ParseFileList(".", []string{"fg/Android.bp", "foo/Android.bp", "ofp/Android.bp"})
 			FailIfErrored(t, errs)
 			_, errs = ctx.PrepareBuildActions(config)
@@ -1224,12 +1224,12 @@
 	config := TestConfig(buildDir, nil, bp, nil)
 	config.TestProductVariables.Allow_missing_dependencies = proptools.BoolPtr(true)
 
-	ctx := NewTestContext()
+	ctx := NewTestContext(config)
 	ctx.SetAllowMissingDependencies(true)
 
 	ctx.RegisterModuleType("test", pathForModuleSrcTestModuleFactory)
 
-	ctx.Register(config)
+	ctx.Register()
 
 	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
 	FailIfErrored(t, errs)