Add helper functions for getting output files from modules

Add OutputFileForModule and OutputFilesForModules to get paths from
OutputFileProducers.

Bug: 122332855
Test: m checkbuild
Change-Id: I2e9aeeb55987742077250390cdb804ba22e79442
diff --git a/android/paths.go b/android/paths.go
index a04dc6b..d181b75 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -89,6 +89,15 @@
 	}
 }
 
+func pathContextName(ctx PathContext, module blueprint.Module) string {
+	if x, ok := ctx.(interface{ ModuleName(blueprint.Module) string }); ok {
+		return x.ModuleName(module)
+	} else if x, ok := ctx.(interface{ OtherModuleName(blueprint.Module) string }); ok {
+		return x.OtherModuleName(module)
+	}
+	return "unknown"
+}
+
 type Path interface {
 	// Returns the path in string form
 	String() string