Re-plumb fuzz corpora.

Re-plumb the fuzz corpora through an intermediates directory.
Previously, due to the way that LOCAL_TEST_DATA is implemented, we would
break when corpora were included:
 a) outside of a corpus/ directory, or
 b) not directly under the module directory (i.e. my_module/subdir/corpus)

Corpora are now written into an intermediates directory so that they
play nice with LOCAL_TEST_DATA, because unfortunately the key-value pair
required there is not as simple as source:destination.

Test: m example_fuzzer && ls \
$ANDROID_PRODUCT_OUT/data/fuzz/arm64/example_fuzzer/corpus
Bug: N/A

Change-Id: I5888b06ed349781c6712f1ae77cc3582283a9552

cc/fuzz.go

@@ -53,9 +53,10 @@ type fuzzBinary struct {
 	*binaryDecorator
 	*baseCompiler
 
-	Properties FuzzProperties
-	corpus     android.Paths
-	dictionary android.Path
+	Properties            FuzzProperties
+	dictionary            android.Path
+	corpus                android.Paths
+	corpusIntermediateDir android.Path
 }
 
 func (fuzz *fuzzBinary) linkerProps() []interface{} {
@@ -103,6 +104,16 @@ func (fuzz *fuzzBinary) install(ctx ModuleContext, file android.Path) {
 	fuzz.binaryDecorator.baseInstaller.install(ctx, file)
 
 	fuzz.corpus = android.PathsForModuleSrc(ctx, fuzz.Properties.Corpus)
+	builder := android.NewRuleBuilder()
+	intermediateDir := android.PathForModuleOut(ctx, "corpus")
+	for _, entry := range fuzz.corpus {
+		builder.Command().Text("cp").
+			Input(entry).
+			Output(intermediateDir.Join(ctx, entry.Base()))
+	}
+	builder.Build(pctx, ctx, "copy_corpus", "copy corpus")
+	fuzz.corpusIntermediateDir = intermediateDir
+
 	if fuzz.Properties.Dictionary != nil {
 		fuzz.dictionary = android.PathForModuleSrc(ctx, *fuzz.Properties.Dictionary)
 		if fuzz.dictionary.Ext() != ".dict" {