Use default match logic to prevent variant fallback bugs, where the requested build is ignored and an alternate is used.

[SVN r34357]

tools/build

@@ -1 +1 @@
-Subproject commit 2c4fc1420de34d752514850a327c9b06442a6870
+Subproject commit df3b8437fa584fe4aa2069db29b17a1fb21ad4af