Xcode has a separate setting for Swift compile definitions, so we can
compute a dedicated value for it. Therefore we can:
* Support the COMPILE_LANGUAGE generator expression for Swift-specific
filters.
* Avoid passing the `=value` part of definitions, which Swift does
not support.
This revises commit 5cb625eb2f (Xcode: Pass compile definitions to
Swift, 2022-06-19, v3.25.0-rc1~493^2) and reverts commit 12c6fec6b4
(Xcode: Drop CMAKE_INTDIR= definition in Swift targets, 2022-09-30,
v3.25.0-rc1~60^2~2), as the latter is no longer needed.
Fixes: #24086
Run the `Utilities/Scripts/clang-format.bash` script to update
all our C++ code to a new style defined by `.clang-format`.
Use `clang-format` version 3.8.
* 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.
Allow the `Swift` language to be enabled with the Xcode generator for
Xcode >= 6.1. Reject it on other generators and with older Xcode
versions. Since Apple is the only vendor implementing the language
right now, the compiler id can be just `Apple`.
