Use the run_cmake() function to generate the test build tree with
the proper CMake generator and also to verify that it succeeds.
Drop our PreTestError helper as it is no longer needed.
The DEPENDENCIES test case uses install(TARGETS) and so generates a warning:
CMake Warning in CMakeLists.txt:
WARNING: Target "test_prog" has runtime paths which cannot be changed
during install. To change runtime paths, OS X version 10.6 or newer is
required. Therefore, runtime paths will not be changed when installing.
CMAKE_BUILD_WITH_INSTALL_RPATH may be used to work around this limitation.
Set CMAKE_BUILD_WITH_INSTALL_RPATH to avoid the warning since we do not
need to run the binaries from the build tree anyway.
The changes in commit 47b060ae (CPackDeb: allow empty directories in
component packages, 2015-09-21), commit b58de9fe (CPack: allow packaging
of empty directories, 2015-09-21), and commit b761e90d (CPack: remove
accidental changes, 2015-09-22) regressed packaging of CMake itself.
Revert the changes until they can be revised and rebased on other
changes that make additional fixes.
Package file names that are found during validation
should be preserved in FOUND_FILE_${NO} variables
that can be later used in custom VerifyResult scripts.
Move PARTIALLY_RELOCATABLE_WARNING test to the new common CPack test
script structure to have all tests in one place as well as additional
benefit of having some more checks done during test execution.