Revert "[SCEV] Enable SCEV verification by default in EXPENSIVE_CHECKS builds"

This reverts commit r301150.  It breaks CodeGen/Hexagon/hwloop-wrap2.ll, reverting
while I investigate.

llvm-svn: 301154
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index a5234b4..1cc0554 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -114,16 +114,9 @@
                         cl::init(100));
 
 // FIXME: Enable this with EXPENSIVE_CHECKS when the test suite is clean.
-static cl::opt<bool> VerifySCEV(
-    "verify-scev",
-    cl::desc("Verify ScalarEvolution's backedge taken counts (slow)"),
-#ifdef EXPENSIVE_CHECKS
-    cl::init(true)
-#else
-    cl::init(false)
-#endif
-  );
-
+static cl::opt<bool>
+VerifySCEV("verify-scev",
+           cl::desc("Verify ScalarEvolution's backedge taken counts (slow)"));
 static cl::opt<bool>
     VerifySCEVMap("verify-scev-maps",
                   cl::desc("Verify no dangling value in ScalarEvolution's "