Externals: Update glslang.

This updates glslang to commit 4fc7a33910fb8e40b970d160e1b38ab3f67fe0f3
which is the current version listed in the known_good.json file for the
version 1.2.131.2 of the Vulkan-ValidationLayers repo.

Externals/glslang/SPIRV/Logger.cpp

@@ -32,6 +32,8 @@
 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // POSSIBILITY OF SUCH DAMAGE.
 
+#ifndef GLSLANG_WEB
+
 #include "Logger.h"
 
 #include <algorithm>
@@ -66,3 +68,5 @@ std::string SpvBuildLogger::getAllMessages() const {
 }
 
 } // end spv namespace
+
+#endif