[Build] Version Header Generation

[AlexandreSinger]

The way that VTR generates its version information creates a file that is used to hold the new version information:

vtr-verilog-to-routing/libs/libvtrutil/CMakeLists.txt

Lines 53 to 80 in 06beac6

	# We always update the vtr_version.cpp file every time the project is built,
	# to ensure the git revision and dirty status are up to date.
	#
	# We need to do this in two stages:
	#
	# 1) We a custom target 'version' (which is always out of date) so it will always be run.
	# It touches the unprocessed version input file so it too will always be out of date.
	#
	# 2) The custom command depends on the touched version input file and generates the processed
	# version file, with updated values. The custom command uses the configure_version.cmake
	# script to generate the up-to-date vtr_version.cpp
	add_custom_target(version ALL
	COMMAND ${CMAKE_COMMAND} -E touch ${VTR_VERSION_FILE_IN})
	add_custom_command(OUTPUT ${VTR_VERSION_FILE_OUT}
	COMMAND ${CMAKE_COMMAND}
	-D IN_FILE=${VTR_VERSION_FILE_IN}
	-D OUT_FILE=${VTR_VERSION_FILE_OUT}
	-D VTR_VERSION_MAJOR=${VTR_VERSION_MAJOR}
	-D VTR_VERSION_MINOR=${VTR_VERSION_MINOR}
	-D VTR_VERSION_PATCH=${VTR_VERSION_PATCH}
	-D VTR_VERSION_PRERELEASE=${VTR_VERSION_PRERELEASE}
	-D VTR_COMPILER_INFO=${VTR_COMPILER_INFO}
	-D VTR_BUILD_INFO=${VTR_BUILD_INFO}
	-P ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules/configure_version.cmake
	MAIN_DEPENDENCY ${VTR_VERSION_FILE_IN}
	WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
	VERBATIM)

This usually works fine, however some users use sudo to build VTR which will cause the build system to create a file that only sudoers can access.

What the VTR build system is doing here is a common enough technique that CMake actually has a utility to do exactly this which should do exactly what we want.

@gadfort Pointed me to how OpenROAD does the exact same thing:

https://github.com/The-OpenROAD-Project/OpenROAD/blob/ac667f3cc7d3904115d0da6836b9df488cee0b8b/CMakeLists.txt#L111-L115

We should move to this simpler interface which should also fix this sudo issue.