Add LLNDK support for the VNDK

Instead of using the NDK headers and libraries, add LL-NDK specific
headers and library stubs for VNDK users. This allows us to provide an
expanded liblog interface.

Test: aosp_arm; m -j
Test: Enable BOARD_VNDK_VERSION on aosp_arm; m -j
Test: Inspect out/soong/build.ninja before/after (w/o vndk)
Change-Id: Ic85f07fa10c695b5baab10c41f5e0ad38700bf3d

cc/ndk_headers.go

@@ -204,6 +204,10 @@ func (m *preprocessedHeaderModule) GenerateAndroidBuildActions(ctx android.Modul
 		ctx.ModuleErrorf("glob %q matched zero files", m.properties.From)
 	}
 
+	processHeadersWithVersioner(ctx, fromSrcPath, toOutputPath, srcFiles, installPaths)
+}
+
+func processHeadersWithVersioner(ctx android.ModuleContext, srcDir, outDir android.Path, srcFiles android.Paths, installPaths []android.WritablePath) android.Path {
 	// The versioner depends on a dependencies directory to simplify determining include paths
 	// when parsing headers. This directory contains architecture specific directories as well
 	// as a common directory, each of which contains symlinks to the actually directories to
@@ -239,10 +243,12 @@ func (m *preprocessedHeaderModule) GenerateAndroidBuildActions(ctx android.Modul
 		ImplicitOutputs: installPaths,
 		Args: map[string]string{
 			"depsPath": depsPath.String(),
-			"srcDir":   fromSrcPath.String(),
-			"outDir":   toOutputPath.String(),
+			"srcDir":   srcDir.String(),
+			"outDir":   outDir.String(),
 		},
 	})
+
+	return timestampFile
 }
 
 func preprocessedNdkHeadersFactory() (blueprint.Module, []interface{}) {