Xcode: Restore Swift include and framework search directories
Previously we selected a single "language for preprocessor" with which
to compute both target-wide GCC_PREPROCESSOR_DEFINITIONS
and
{HEADER,FRAMEWORK}_SEARCH_PATHS
. Since !7826 (merged) we never compute GCC_PREPROCESSOR_DEFINITIONS
for
Swift. Therefore we need to select the language for target-wide include
directories separately.
Also populate Xcode's SWIFT_INCLUDE_PATHS
build setting with the target-wide include directories.
Fixes: #24116 (closed)
Backport: release
Edited by Brad King