Fix the SmartBSTR copy constructor and copy assignment operator added by
commit 18c8278b62 (VS: Add helper class to interact with Visual Studio
Installer, 2016-12-14, v3.8.0-rc1~93^2~4) to use the string from the
source of the copy.
Issue: #19610
Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`. Use `clang-format` version 6.0.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
The `Microsoft.VisualStudio.Component.VC.Tools.x86.x64` component is
not the only way a VS instance may provide the `cl` compiler tool.
For example, VS 2017 Express Edition does not install that component.
Instead search for the tools directly on disk within an instance.
Suggested-by: Rich Chiodo <rchiodo@microsoft.com>
Fixes: #17349
VS 2017 exports a COM component which can be queried to find if VS 2017
is installed and also other components such as VC toolset and Windows
SDKs. Add a helper class to interact with this interface.
