Handle arch-specific/not properties the same.

Refactor arch-handling code to return a "no-config" axis which allows
handling non-arch configed properties the same way as arch-configed
properties.

Test: build/bazel/ci/bp2build.sh
Change-Id: I485b35fd91c28501fe2055234dc9b278488bf4b5
diff --git a/cc/compiler.go b/cc/compiler.go
index 03214c8..34d68a1 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -261,8 +261,12 @@
 	return []interface{}{&compiler.Properties, &compiler.Proto}
 }
 
+func includeBuildDirectory(prop *bool) bool {
+	return proptools.BoolDefault(prop, true)
+}
+
 func (compiler *baseCompiler) includeBuildDirectory() bool {
-	return proptools.BoolDefault(compiler.Properties.Include_build_directory, true)
+	return includeBuildDirectory(compiler.Properties.Include_build_directory)
 }
 
 func (compiler *baseCompiler) compilerInit(ctx BaseModuleContext) {}