Add some utilities for UNITY_BUILD

- The following commands accepts NO_UNITY_BUILD, and
  NO_UNITY_BUILD_SOURCES arguments to opt out of the unity build, and
  to exclude some source files from unity build, respectively.
  - qt_internal_add_executable
  - qt_internal_add_module
  - qt_internal_add_plugin
  - qt_internal_add_tool
  - qt_internal_extend_target
  - qt_internal_add_common_qt_library_helper
  - qt_internal_add_cmake_library
  - qt_internal_add_simd_part
- Unity build is disabled by default in these:
  - qt_internal_add_test
  - qt_internal_add_test_helper
  - qt_internal_add_benchmark
  - qt_internal_add_3rdparty_library
- qt_update_ignore_pch_source also excludes the files from unity_build

Pick-to: 6.5
Task-number: QTBUG-109394
Change-Id: I5d0e7df633738310a015142a6c73fbb78b6c3467
Reviewed-by: Alexandru Croitor <[email protected]>

0 files changed, 0 insertions, 0 deletions