Clean up dead loops before suspend check elimination.

Get rid of BasicBlock::KillUnreachable() and just Kill()
unreachable blocks from the DFS order calculation.

Bug: 18718277
Change-Id: Icaf7b9c2320530e950f87e1e2e2bd1fa5f53cb98
diff --git a/test/800-smali/smali/b_18718277.smali b/test/800-smali/smali/b_18718277.smali
new file mode 100644
index 0000000..b14ad20
--- /dev/null
+++ b/test/800-smali/smali/b_18718277.smali
@@ -0,0 +1,29 @@
+.class public LB18718277;
+
+.super Ljava/lang/Object;
+
+.method public static helper(I)I
+    .locals 1
+    add-int/lit8 v0, p0, 2
+    neg-int v0, v0
+    return v0
+.end method
+
+.method public static getInt()I
+    .registers 2
+    const/4 v1, 3
+    invoke-static {v1}, LB18718277;->helper(I)I
+    move-result v0
+    :outer_loop
+    if-eqz v1, :exit_outer_loop
+    const/4 v0, 0
+    if-eqz v0, :skip_dead_loop
+    :dead_loop
+    add-int/2addr v0, v0
+    if-gez v0, :dead_loop
+    :skip_dead_loop
+    add-int/lit8 v1, v1, -1
+    goto :outer_loop
+    :exit_outer_loop
+    return v0
+.end method