Changes for SCons#4312:
* The installed VCS list is cached but has an indirect dependency on the value of the environment's TARGET_ARCH during construction.  For the initial construction, force the env['TARGET_ARCH'] to be undefined and then restore the value after construction.
* Protect against an empty regular expression list when iteratively removing default tool sequences.

Changes for ARM64 host support:
* Add configuration data structures to support ARM64 hosts and ARM64 native tools for VS2022.  Update the tests for the renamed data structures.
* Evaluate the PROCESSOR_ARCHITECTURE value from the windows registry before evaluating the os environment values for host architecture determination on Windows.
* Set VSCMD_SKIP_SENDTELEMETRY=1 for arm32 process on arm64 host if not already defined to prevent powershell dll not found error.
* The os environment variable value for PROCESSOR_ARCHITECTURE is AMD64 for Windows ARM64 hosts when using a python built for AMD64.

Related MSVC changes for SCons#4312 and ARM64 hosts:
* Check that cl.exe exists in find_batch_file for VS6 to VS2015.  Move the sdk batch file query code to its own function.  Query for the sdk batch file only when all of the vc script host/target combinations have been exhausted and a valid script has not been found.
* Hoist the query for the vc product directory outside the current vc script host/target loop.  Catch the internal exceptions as before.
* Clear the sdk batch file path for VCForPython as the sdk batch files do not appear to be updated during installation and do not point to the VCForPython installation location.
* Move the sdk batch file determination to its own function.  Defer evaluation of candidate sdk batch files until after all host/target combinations of the vc scripts have been evaluated.
* Always check that cl.exe is found in vc script environment path.

Miscellaneous:
* Reorder and group exception definitions in Tool\MSCommon\vc.py by external exceptions and internal exceptions.
* Adjust debug messages.
* Convert the floating point msvc version to an integer version number for product range comparisons (e.g., 14.3 is 143).  Adjust the comparison ranges accordingly.

…dule reset when debug logging is enabled.

…er to be consistent with the current documentation of MSVS_ARCH.

Update the documentation for HOST_ARCH.

Manually resolve conflicts in CHANGES.txt.

First query the windows registry for the processor architecture and then fallback to the platform machine architecture. The platform.machine() architecture return value for an amd64 build of python (3.6.8) on arm64 is amd64.

Update the _ARCH_TO_CANONICAL dictionary from Tool\MSCommon\vc.py.

Manually resolve conflicts in CHANGES.txt.

Manually resolve conflicts:
* SCons/Tool/MSCommon/common.py

Manually resolve conflicts in CHANGES.txt and RELEASE.txt.

Manually resolve conflicts in RELEASE.txt.