Misc test cleanups.

* tbaa-struct.cpp always has a 64 bit pointer.
* f32:32:32, f64:64:64 and f128:128:128 are defaults, don't assume they are
  printed.
[Stackmap] The first integer argument is passed in register for the WebKit_JS calling convention.

Pass the first integer argument (callee) in register to optimize inline caches.