Minor cc_cmake_snapshot touch-ups

- Partial support for arm64 hosts (no prebuilts yet)
- Replace incorrect template function use MATCHES with STREQUAL
- Add more ignored system libs
- No need to explicitly add libc++ prebuilt

Bug: 285204695
Test: m binder_sdk
Change-Id: Id6508cc9f9ee6328c95c2821c325629f84eda138

cc/cmake_snapshot.go

@@ -61,8 +61,13 @@ var defaultUnportableFlags []string = []string{
 }
 
 var ignoredSystemLibs []string = []string{
+	"crtbegin_dynamic",
+	"crtend_android",
+	"libc",
 	"libc++",
 	"libc++_static",
+	"libdl",
+	"libm",
 	"prebuilt_libclang_rt.builtins",
 	"prebuilt_libclang_rt.ubsan_minimal",
 }
@@ -267,7 +272,11 @@ func (m *CmakeSnapshot) DepsMutator(ctx android.BottomUpMutatorContext) {
 		{"arch", "x86_64"},
 	}
 	ctx.AddVariationDependencies(variations, cmakeSnapshotModuleTag, m.Properties.Modules...)
-	ctx.AddVariationDependencies(variations, cmakeSnapshotPrebuiltTag, m.Properties.Prebuilts...)
+
+	if len(m.Properties.Prebuilts) > 0 {
+		prebuilts := append(m.Properties.Prebuilts, "libc++")
+		ctx.AddVariationDependencies(variations, cmakeSnapshotPrebuiltTag, prebuilts...)
+	}
 }
 
 func (m *CmakeSnapshot) GenerateAndroidBuildActions(ctx android.ModuleContext) {