CI updates.
* js/azure-pipelines-msvc:
ci: also build and test with MS Visual Studio on Azure Pipelines
ci: really use shallow clones on Azure Pipelines
tests: let --immediate and --write-junit-xml play well together
test-tool run-command: learn to run (parts of) the testsuite
vcxproj: include more generated files
vcxproj: only copy `git-remote-http.exe` once it was built
msvc: work around a bug in GetEnvironmentVariable()
msvc: handle DEVELOPER=1
msvc: ignore some libraries when linking
compat/win32/path-utils.h: add #include guards
winansi: use FLEX_ARRAY to avoid compiler warning
msvc: avoid using minus operator on unsigned types
push: do not pretend to return `int` from `die_push_simple()`