Add synthesize uses at back edge.
This reduces the cost of linearizing the graph (hence removing
the notion of back edge). Since linear scan allocates/spills registers
based on next use, adding a use at a back edge ensures we do count
for loop uses.
Change-Id: Idaa882cb120edbdd08ca6bff142d326a8245bd14
diff --git a/test/482-checker-loop-back-edge-use/info.txt b/test/482-checker-loop-back-edge-use/info.txt
new file mode 100644
index 0000000..f7fdeff
--- /dev/null
+++ b/test/482-checker-loop-back-edge-use/info.txt
@@ -0,0 +1,2 @@
+Tests the register allocator's optimization of adding synthesized uses
+at back edges.