* Move DacTableGen out of the CMake build and into tools-local.

* Attempt: usenmakefiles means ninja.

* Make changes to Windows build to support non-VS generators like ninja.

* Use CMake 3.16 PCHs.

* Remove explicit process count.

* Build and run DacTableGen via the .NET CLI we pull down for the build instead of via CMake.

* Update configurecompiler.cmake to specify language (needed for Ninja).
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Get Ninja build working again.

* Pass configuration to cmake configure step for Ninja build.

* Rename flag

* Fix configure step for cross-arch native build
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Support building via Ninja for coreclr via an MSBuild property
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Implement support for opening the CoreCLR solution in VS via the -vs flag.

* Fix setting generator to Ninja.

* Merge libraries gen-buildsys-win.bat with runtime gen-buildsys.cmd to share windows cmake configure infra.

* Enable building libraries native build with ninja.

* Centralize setting CMAKE_SYSTEM_VERSION for windows builds.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Update host build to use shared gen-buildsys.cmd

* Fix multi-config generator detection.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Exit with success when we build successfully.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Enable and fix up Ninja build for hosts.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Only link delayimp.lib on Windows
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Remove "overriding /W3 with /W1" warning in Ninja build of hosts by turning on /W3 and disabling any new warnings we hit.

* Reduce command line override warnings by adopting the MSVC_RUNTIME_LIBRARY abstraction feature in CMake 3.14+ (below the minimum requirement on Windows).

* Use the delayed expansion syntax to correctly pass in the config to cmake.

* Move all usages of MSVC runtime library selection to the CMake abstraction to reduce console spew about overridden flags.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Condition the rest of the compiler options correctly so they don't show up as invalid parameter warnings for assembly builds.

* Correctly build DIALib and DacTableGen as AnyCPU

* Fix WRITE_BARRIER_CHECK define
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Fix passing arch for MSBuild build.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Configure ASM compiler command line format in configurecompiler.cmake and use CMake's assembly compilation step to build ASM files for ARM/ARM64 instead of manually building them and adding the generated files as additional sources.

* Cleanup after fixing ARM/ARM64 support.

* Rename variable

* Condition PCH's for C++-only as needed to fix using them on non-Windows (where we compile C as C instead of as C++).

* Fix CoreCLR native test build on windows to point to new gen-buildsys location.

* Add missing compilation options in Ninja build that are implicitly defined in the MSBuild build.

* Disable analyzers for DacTableGen. Remove /MAP linker flag (that's for local testing).

* Upgrade to CMake 3.16.4

* Don't warn on unused variables in CMake (these usually vary on platform/config)
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Manually compile ARM and ARM64 asm files when using the VS generator since it doesn't support emitting MARMASM item types in projects (and as a result cannot compile ARM or ARM64 asm without assistance).

* Enable CMake policy in test build to use CMAKE_MSVC_RUNTIME_LIBRARY variable.

* Update initially disabled warnings in host.

* Add -ninja arg to root scripts to enable using Ninja.

* Enable using Ninja in CoreCLR CI.

* Try to fix passing the -ninja arg in yaml.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Add ninja to the Windows invocation

* Fix 2-phase cross targeting to do one phase at a time and initialize the VC++ environment for the correct build tools each time instead of interleaving them and relying on Visual Studio to handle the differing targets.

* Restore old /Ox optimization setting for Release.

* Fix typos, don't pass exception flags to C files.

* Remove unneeded pragma.

* Fix .pgd file installation.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Add mention of the `-ninja` flag in the Building CoreCLR documentation.
Signed-off-by: NJeremy Koritzinsky <jekoritz@microsoft.com>

* Mention installation locations for Ninja and warn while building if CMake is older than 3.16.0.

* Update docs/workflow/requirements/windows-requirements.md