Add glslang (#4463)

* Add glslang

* Add compatibility line

* Remove core packages from depends

packages/glslang.rb

+# Adapted from Arch Linux glslang PKGBUILD at:
+# https://github.com/archlinux/svntogit-packages/raw/packages/glslang/trunk/PKGBUILD
+
+require 'package'
+
+class Glslang < Package
+  description 'OpenGL and OpenGL ES shader front end and validator'
+  version '8.13.3743'
+  compatibility 'all'
+  source_url 'https://github.com/KhronosGroup/glslang/archive/8.13.3743.tar.gz'
+  source_sha256 '639ebec56f1a7402f2fa094469a5ddea1eceecfaf2e9efe361376a0f73a7ee2f'
+
+  def self.build
+    system "./update_glslang_sources.py"
+    
+    Dir.mkdir 'build-shared'
+    Dir.chdir 'build-shared' do
+      system "cmake .. \
+      -GNinja \
+      -DCMAKE_INSTALL_PREFIX=#{CREW_PREFIX} \
+      -DCMAKE_INSTALL_LIBDIR=#{CREW_LIB_PREFIX} \
+      -DCMAKE_BUILD_TYPE=Release \
+      -DBUILD_SHARED_LIBS=ON"
+    end
+    system 'ninja -C build-shared'
+    
+    Dir.mkdir 'build-static'
+    Dir.chdir 'build-static' do
+    system "cmake .. \
+      -GNinja \
+      -DCMAKE_INSTALL_PREFIX=#{CREW_PREFIX} \
+      -DCMAKE_INSTALL_LIBDIR=#{CREW_LIB_PREFIX} \
+      -DCMAKE_BUILD_TYPE=Release \
+      -DBUILD_SHARED_LIBS=OFF"
+      end
+    system 'ninja -C build-static'
+  end
+
+  def self.install
+  system "DESTDIR=#{CREW_DEST_DIR} ninja -C build-shared install"
+  system "DESTDIR=#{CREW_DEST_DIR} ninja -C build-static install"
+  end
+end