clean up experimental setup and keep using ffast-math flag

Summary: Remove experimental setup of fast-math and add `-ffast-math` as a compiler flag for yoga.

Reviewed By: emilsjolander

Differential Revision: D7414228

fbshipit-source-id: 320e1b1953f6af867b13e617af7872eb8999160e

java/com/facebook/yoga/YogaConfig.java

@@ -16,11 +16,7 @@ public class YogaConfig {
   public static int SPACING_TYPE = 1;
 
   static {
-    if (YogaConstants.shouldUseFastMath) {
-      SoLoader.loadLibrary("yogafastmath");
-    } else {
       SoLoader.loadLibrary("yoga");
-    }
   }
 
   long mNativePointer;

java/com/facebook/yoga/YogaConstants.java

@@ -18,8 +18,6 @@ public class YogaConstants {
    */
   public static final float UNDEFINED = (float) (10E20);
 
-  public static boolean shouldUseFastMath = false;
-
   public static boolean isUndefined(float value) {
     // Value of a float in the case of it being not defined is 10.1E20. Earlier it used to be NAN,
     // the benefit of which

java/com/facebook/yoga/YogaNode.java

@@ -17,11 +17,7 @@ import javax.annotation.Nullable;
 public class YogaNode implements Cloneable {
 
   static {
-    if (YogaConstants.shouldUseFastMath) {
-      SoLoader.loadLibrary("yogafastmath");
-    } else {
       SoLoader.loadLibrary("yoga");
-    }
   }
 
   /**