Replace our hard-coded defaults for `/MD` and `/MDd` with a first-class
abstraction to select the runtime library from an enumeration of logical
names.  We've long hesitated to do this because the idea of "runtime
library selection" touches on related concepts on several platforms.
Avoid that scope creep by simply defining an abstraction that applies
only when targeting the MSVC ABI on Windows.

Removing the old default flags requires a policy because existing
projects may rely on string processing to edit them and choose a runtime
library under the old behavior.  Add policy CMP0091 to provide
compatibility.

Fixes: #19108

Fixes: #18998

Also support installing headers on an INTERFACE library.
Signed-off-by: Avraham Shukron <avraham.shukron@gmail.com>
Fixes: #15234

These capabilities complement MR !3190
and is also needed to solve issue #18771.

The test project does not compile any sources and so does not
need to enable any languages.

The `-S` and `-B` command-line option tests do generate build systems
and so should use the generator being tested.

In some cases GCC reports *relative* implicit include directories.  They
are computed adaptively with respect to the current working directory
such that the effective implicit include directory is an unchanging
absolute path.  Teach our implicit include directory extraction to
recognize such paths and normalize them.

Fixes: #19133

This new capability is required to solve efficiently issue #18771

The implicit include directory extraction added by commit 5990ecb7
(Compute implicit include directories from compiler output, 2018-12-07,
v3.14.0-rc1~108^2) leaves paths like `/usr/lib/../include` unchanged.
Fix the logic to canonicalize such paths (e.g. to `/usr/include`)
as we do for implicit link directories already.  This is important
to ensure the set of implicit directories is represented in the same
form as the include directories that will be compared to them.

Issue: #19095

Any `include_directories()` calls in toolchain files are used during our
ABI detection step even though it does not include any system headers.
Since commit 5990ecb7 (Compute implicit include directories from
compiler output, 2018-12-07, v3.14.0-rc1~108^2), that check is also used
to detect implicit include directories.  Any `include_directories()` in
a toolchain file are detected as implicit and later excluded from
explicit specification on compiler command lines, thus breaking the
purpose of the calls in the first place.

Fix the implicit include directory detection step to avoid using paths
from `include_directories()` calls in the toolchain file.

Fixes: #19079

Fixes: #18968

Fixes: #15805

Issue: #15805

Rationale:
Currently during creation of archive by 'tar',
if error appears, it interrupt archive creation.
As a result only part of files are archived

This behaviour is not consistent with 'copy_directory', native 'tar'
and other command behaviour.
With this Merge Request this behaviour is fixed.

Fixes: #19023

Do not `find_package(GTK2)` by default, as it gives the impression that
CMake depends on it to build.  We will set `CMake_TEST_FindGTK2` in the
cache of automated builds where GTK2 is expected to work.

Extend the genex added by commit ca6ba3fe (Genex: Add a SHELL_PATH
expression, 2015-09-24, v3.4.0-rc1~37^2) to accept a `;`-list of paths,
convert them all, and generate a list separated by the native shell
`PATH``` separator.

Since commit e89ad0f9 (install: Allow installing targets created in
another directory, 2018-06-18, v3.13.0-rc1~407^2) the `install(TARGETS)`
command may find a global-scoped target outside the calling directory.
Ignore an `IMPORTED GLOBAL` target if it is found in this way.  Imported
targets cannot be installed, and trying to do so violates internal
invariants.

Fixes: #19022

Since commit 11da882a (Apple: Introduce separate system name for iOS,
tvOS, and watchOS, 2018-01-15, v3.14.0-rc1~14^2~1) we support setting
`CMAKE_SYSTEM_NAME` to `iOS`.  Existing iOS toolchain files already
set `IOS` as a short-hand variable, so do the same here.

Fixes: #16136

This also adds a test to enforce the order behavior of
list(REMOVE_DUPLICATES).

Fixes: #18990

The change in commit a5dd1599 (Tests: Fix RunCMake.try_compile
CxxStandard case on MSVC, 2017-09-22, v3.10.0-rc1~63^2) introduced use
of `if()` conditions not supported until CMake 3.7, so while it was
intended to restore support for CMake versions prior to 3.9, it actually
only did so for 3.7 and 3.8.  Backport the logic to work with CMake 3.1.

Fixes: #18987

Add a `VS_NO_SOLUTION_DEPLOY` target property to explicitly specify for
each target whether to suppress VS solution deployment of the generated
target project.

Fixes: #18953