Simplify InternalPreconditions.

Earlier the chaining of the variables required too many passes to optimize
and propogate constants. The patch reduces inter-depdency so constants
are resolved much quicker.

Change-Id: Ib4a9719b240b42eaa387862bdda91e0b9f862cfb
diff --git a/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java b/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java
index 65b498f..6e3f66f 100644
--- a/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java
+++ b/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java
@@ -83,10 +83,13 @@
       getProperty("jre.checks.checkLevel") == "NORMAL";
   // NORMAL or OPTIMIZED
   private static final boolean LEVEL_OPT_OR_HIGHER =
-      getProperty("jre.checks.checkLevel") == "OPTIMIZED" || LEVEL_NORMAL_OR_HIGHER;
+      getProperty("jre.checks.checkLevel") == "OPTIMIZED"
+          || getProperty("jre.checks.checkLevel") == "NORMAL";
   // NORMAL or OPTIMIZED or MINIMAL
   private static final boolean LEVEL_MINIMAL_OR_HIGHER =
-      getProperty("jre.checks.checkLevel") == "MINIMAL" || LEVEL_OPT_OR_HIGHER;
+      getProperty("jre.checks.checkLevel") == "MINIMAL"
+          || getProperty("jre.checks.checkLevel") == "OPTIMIZED"
+          || getProperty("jre.checks.checkLevel") == "NORMAL";
 
   static {
     if (!LEVEL_MINIMAL_OR_HIGHER) {