tracing: Work around an LLVM bug on Windows

Clang/LLVM doesn't allow evaluating the address of a dllimport symbol
in a constexpr context, e.g.:

  extern __declspec(dllimport) int x;
  constexpr int* y = &x;

This causes a compilation error when trying to pass the array of
per-tracing category enabled state bits to the the constexpr
TrackEventCategoryRegistry while PERFETTO_COMPONENT_EXPORT is
set to __declspec(dllimport).

Luckily, since 2c297b36 the constexpr category registry doesn't
actually need access to the per-category enabled state, so we can work
around this by not passing this data to the registry in the first place.

See https://bugs.llvm.org/show_bug.cgi?id=51558 for the upstream
LLVM bug.

Bug: 189825391
Change-Id: Ib2ececf36dd2b2f16b8633c8ec000c85247d72db