Merge topic 'custom-command-CROSSCOMPILING_EMULATOR'

Help/command/add_custom_command.rst

Help/command/add_custom_target.rst

Help/prop_tgt/CROSSCOMPILING_EMULATOR.rst

Help/release/dev/custom-command-CROSSCOMPILING_EMULATOR.rst

Source/cmCustomCommandGenerator.cxx

Source/cmCustomCommandGenerator.h

Tests/RunCMake/CMakeLists.txt

...CrosscompilingEmulator/AddCustomCommand-build-check.cmake

Tests/RunCMake/CrosscompilingEmulator/AddCustomCommand.cmake

.../CrosscompilingEmulator/AddCustomTarget-build-check.cmake

Tests/RunCMake/CrosscompilingEmulator/AddCustomTarget.cmake

Tests/RunCMake/CrosscompilingEmulator/RunCMakeTest.cmake

...unCMake/CrosscompilingEmulator/simple_src_exitsuccess.cxx

Tests/RunCMake/pseudo_emulator_custom_command.c