Removing FindQt.cmake gives Qt upstream a path forward to export its
own QtConfig.cmake files which can be found by find_package()
without having to explicitly specify CONFIG. Projects that still
want to use Qt3/4 can call find_package(Qt[34]), include(FindQt),
or add FindQt.cmake to their CMAKE_MODULE_PATH.

c4b4d8b3 POSITION_INDEPENDENT_CODE: Manage link flags for executables
724a0346 POSITION_INDEPENDENT_CODE: Fix erroneous '-fPIE' flag for Sun Studio
023188ff INTERFACE_POSITION_INDEPENDENT_CODE: add generator expressions support
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2465

0e97ef74 Autogen: Add release notes for CMAKE_GLOBAL_AUTOGEN/RCC_TARGET
2ef8fe22 Autogen: Add documentation for CMAKE_GLOBAL_AUTOGEN/RCC_TARGET
8c8731b4 Autogen: Add test for CMAKE_GLOBAL_AUTOGEN/RCC_TARGET
3baa817c Autogen: Add support for global ``autogen`` and ``autorcc`` targets
3327d3bb Autogen: Add cmQtAutoGenGlobalInitializer class
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2567

4e4551f9 FindODBC: Do not assume odbc32.lib for MinGW
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2585

1320122d FindICU: Add libdl to the link libraries for icu-uc
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Francois Budin <francois.budin@kitware.com>
Merge-request: !2581

c84fb481 ASM: Detect compiler id for Clang used as Assembler
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2584

b71667a3 FindBoost: Improve compiler prefix detection for GCC 5+ and clang 4+
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2579

Fixes: #14983, #16561

This teaches CMake the variables

- CMAKE_GLOBAL_AUTOGEN_TARGET
- CMAKE_GLOBAL_AUTOGEN_TARGET_NAME
- CMAKE_GLOBAL_AUTORCC_TARGET
- CMAKE_GLOBAL_AUTORCC_TARGET_NAME

which control the generation of global
``autogen`` and ``autorcc`` targets.

Closes #17721

This moves the global ``AUTOMOC/UIC/RCC`` targets initializer
generation code into a separate new ``cmQtAutoGenGlobalInitializer`` class.

For MinGW, do not look for odbc32.lib but allow search for libodbc32.a.

Fixes: #18539

Merge-request: !2579

Add recognition of compiler version and prefix for clang.
Accommodate changes to version numbering scheme for GCC 5+ and clang 4+
 - Minor number becomes patch, so excluded it from compiler prefix.
 - Improves searching for Boost 1.69+ libraries built with GCC 5+ and
   clang 4+, where library names are generated with compiler tag based on
   major version only eg. -gcc5 for GC 5.5.0 or -clang6 for clang 6.0.0
 - Follows up related changes in upcoming Boost 1.69
   https://github.com/boostorg/build/pull/349
Dump detected compiler version in Boost_DEBUG message.
Replace use of CMAKE_COMPILER_IS_GNUCXX with CMAKE_CXX_COMPILER_ID.

Merge-request: !2584

Merge-request: !2570

bd831ed0 FindBoost: Add system thread library to Boost_LIBRARIES
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2570

Add missing vendor table entries for Clang and AppleClang to identify
them.  Previously this worked only if Clang was also enabled as a C or
CXX compiler first because we used to copy the C compiler id.  However,
that was removed by commit v3.13.0-rc1~44^2 (ASM: Search for full path
even when using C or C++ compiler, 2018-09-26).

Fixes: #18575

Add the system thread library to Boost_LIBRARIES when the boost thread
component has been found.

The Boost::thread imported target already pulls in Threads::Threads.
This changes does the same for projects using the Boost_LIBRARIES variable
instead.

f29e2292 cpack: When given an unknown generator print out all valid generators
eba7273c cpack: Better error message when generator doesn't exist.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: David Cole <dlrdave@aol.com>
Merge-request: !2580

86033849 Help: Describe $CACHE and $ENV as operators
e855bd52 Help: Document if(DEFINED ENV{name})
8ba2a8d4 Help: short/long variable reference in if command
85498fcc Help: Provide backreferences.
e24ef969 Help: New section on Environment Variables in cmake-language.7
e4554149 Help: Remove over-precise clause.
3de551cc Help: Clarify effect of set(ENV{..} ..) and unset(ENV{..})
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2538

This makes cpack behavior match cmake when passed an invalid generator

This resolves issue #18514

Also add a cross-reference to if(DEFINED ENV{var}).

Explain that the short form of variable references
in the if command does not apply to ENV and CACHE vars.

Short intro to pages cmake-variables.7 and cmake-env-variables.7,
with backlinks to cmake-language.7.

Section "Variables References" said that environment and cache
variables are "evaluated in the same contexts as a normal variable
reference". The reader has to guess what "contexts" means in
this context. Probably "inside a Quoted Argument or an Unquoted
Argument", exactly as for ordinary variable references.
But this is exactly what the reader would tacitly assume anyway.
Therefore I think the removed clause was unnecessary, and possibly
more confusing than helpful.

Explain that the commands affect only the current CMake process,
not the process from which CMake was called,
nor the system environment at large,
nor the environment of subsequent build or test processes.

Currently the CPack error message when passed an invalid generator
name  reads like the generator failed to work, rather than the
name was invalid.

Fixes: #16311