Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`, now with "east const" enforcement.
Use `clang-format` version 18.
* 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.
Issue: #26123
Place `.swiftmodule` files a subdirectory named after the configuration.
Fixes: #25864Fixes: #25997
- Swift/RunCMakeTest.cmake:
- CMP0157-OLD was enabled for Xcode, where it works.
- A test was added that verifies .swiftmodule's are generated into
separate directories with multi-config generators.
- Tests/SwiftOnly/CMakeLists.txt: tests were added that validate that
cross-subdirectory module dependencies (via target_link_libraries)
work.