Removed all the Statistics code.

I think we should acknowledge this is the wrong way to approach
the issue. Statistics can be gathered in a way which does not
pollute the compiler codebase and is not rigidly tied into
statically generated logic, via instrumentation. Here are some
reasons why this code should go:

 - it greatly obfuscates the logic of key methods
 - it is untested
 - it cannot even be enabled without recompiling
 - it is inflexible in other ways
 - it is almost certainly hurting performance

As to the last point, are we really that confident that a
difference like this in a hot method isn't going to have any
impact? I'm definitely not.

```diff
-        : getstatic     #                 // Field util/Statistics$.MODULE$:Lutil/Statist
-        : invokevirtual #                 // Method util/Statistics$.canEnable:()Z
-        : ifeq
-       : getstatic     #                 // Field util/Statistics$.MODULE$:Lutil/Statisti
-       : getstatic     #                 // Field TypesStats$.MODULE$:LTypesStats$;
-       : invokevirtual #                 // Method TypesStats$.findMembersCount:()Lutil/S
-       : invokevirtual #                 // Method util/Statistics$.incCounter:(Lutil/St
-       : getstatic     #                 // Field util/Statistics$.MODULE$:Lutil/Statisti
-       : invokevirtual #                 // Method util/Statistics$.canEnable:()Z
-       : ifeq
-       : getstatic     #                 // Field util/Statistics$.MODULE$:Lutil/Statisti
-       : getstatic     #                 // Field TypesStats$.MODULE$:LTypesStats$;
-       : invokevirtual #                 // Method TypesStats$.typeOpsStack:()Lutil/Stati
-       : new           #                 // class Types$Type$$anonfun$
-       : dup
-       : invokespecial #                 // Method Types$Type$$anonfun$ ."<init>":(LTypes
-       : invokevirtual #                 // Method util/Statistics$.pushTimer:(Lutil/Stat
-       : goto
-       : aconst_null
-       : astore
-       : lload_3
-       : lstore
-       : lload_1
-       : ldc _w        #                 // long  l
+        : lload_3
+        : lstore
+        : lload_1
+        : ldc _w        #                 // long  l
```