This commit generates a `gnustep-base.pc` file which is installed in `/lib/pkgconfig` and contains the GNUstep base version number, the libraries to link (equivalent to `gnustep-config --base-libs`) with and the C flags to use (equivalent to `gnustep-config --objc-flags`).
Removes dependency on pthread library and uses fast Slim Reader/Writer (SRW) locks for NSLock/NSRecursiveLock/NSCondition/NSConditionLock as well as all internal locks. Adds GS_MUTEX_*() macros in GSPThread.h, that are being used for all internal locking instead of pthread APIs.
Also adds support for thread priorities on Windows, fixes method signature of +[NSThread setThreadPriority:] to match Apple platforms, and adds error handling in same method.
Requires passing the activity's AssetManager object from Java to GNUstep by calling +[NSBundle setJavaAssetManager:withJNIEnv:], which then enables the following features:
- NSBundle main bundle resource paths support for Android assets, e.g. for pathForResource:ofType:, URLForResource:ofType: and related methods.
- NSBundle main bundle info dictionary support if Info.plist exists in Android assets.
- -initWithContentsOfFile: and related methods support for reading Android assets from main bundle in various classes (e.g. NSData, NSDictionary, NSArray, etc.).
- NSFileManager fileExistsAtPath:(isDirectory:) and isReadableFileAtPath: return YES for main bundle asset / asset directory paths.
- NSFileHandle support for reading Android assets from main bundle.
- NSDirectoryEnumerator support for enumerating Android assets from main bundle. Note that recursion into subdirectories is currently not supported by the native Android asset manager API (see https://issuetracker.google.com/issues/37002833).
Also adds support for automatic NSProcessInfo initialization on Android with a fake executable path "/data/data/<app identifier>/exe" (as Android apps don't have a real executable path), and tweaks main bundle initialization to allow that path. Main bundle resource paths are prefixed by "/data/data/<app identifier>/Resources".
This updates the libdispatch runloop integration to be compatible with the Swift corelibs libdispatch release:
https://github.com/apple/swift-corelibs-libdispatch
In that release, the main queue handle and drain functions have been renamed with a "_4CF" (for CoreFoundation) suffix and have moved to private.h, so we now check for the existance of this header and function names.
Note that libdispatch must be compiled with INSTALL_PRIVATE_HEADERS=YES.
Also fixes the checks for the HAVE_LIBDISPATCH_RUNLOOP define (was inverted) and ensures that both the handle and drain functions are available.
