Enable -bigobj on MSVC

Enable -bigobj on MSVC

This fixes this error:

  C:\lo\src\core\sc\qa\unit\ucalc_copypaste.cxx : fatal error C1128: number of sections exceeded object file format limit: compile with /bigobj

According to [1], it is enabled by default in all UWP projects, which
presumably means there's no harm in enabling it (other than some
compiling overhead, which impact is unclear at the moment).

Enabling it unconditionally, it would not create a mismatch like in
7788e87ce25183c1d6f92a3b972b8dd8c88e58e3.

[1] https://docs.microsoft.com/en-us/cpp/build/reference/bigobj-increase-number-of-sections-in-dot-obj-file

Change-Id: Id176add21fec2a6084149e9ff23bdafb10b3d579
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/116454
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>