Add SDK member support for cc_object.

Test: m nothing
Test: Add
    sdk {
        name: "runtime-module-sdk",
        native_shared_libs: [
            "libc",
            "libdl",
            "libm",
            "ld-android",
        ],
        native_objects: [
            "crtbegin_dynamic",
            "crtbegin_static",
            "crtend_android",
        ],
    }
  to bionic/apex/Android.bp. Then:
    build/soong/scripts/build-aml-prebuilts.sh runtime-module-sdk
  Take the generated runtime-module-sdk-current.zip and unzip into a
  master-art tree without bionic/, edit the generated Android.bp to
  extend cc_prebuilt_* modules with:
    nocrt: true,
    stl: "none",
    system_shared_libs: [],
    apex_available: ["//apex_available:anyapex"],
    recovery_available: true,
    vendor_available: true,
    ramdisk_available: true,
  Then "m com.android.art.debug". This passes Soong but fails in the
  build step because more members are required.
Bug: 148934017
Change-Id: I2ab8f6aadb1440b325697cae4a8ed761c62d15d2
diff --git a/android/sdk.go b/android/sdk.go
index 5c7b329..731bdff 100644
--- a/android/sdk.go
+++ b/android/sdk.go
@@ -304,10 +304,11 @@
 	// SdkAware and be added with an SdkMemberTypeDependencyTag tag.
 	HasTransitiveSdkMembers() bool
 
-	// Add dependencies from the SDK module to all the variants the member
-	// contributes to the SDK. The exact set of variants required is determined
-	// by the SDK and its properties. The dependencies must be added with the
-	// supplied tag.
+	// Add dependencies from the SDK module to all the module variants the member
+	// type contributes to the SDK. `names` is the list of module names given in
+	// the member type property (as returned by SdkPropertyName()) in the SDK
+	// module. The exact set of variants required is determined by the SDK and its
+	// properties. The dependencies must be added with the supplied tag.
 	//
 	// The BottomUpMutatorContext provided is for the SDK module.
 	AddDependencies(mctx BottomUpMutatorContext, dependencyTag blueprint.DependencyTag, names []string)