Update Linux CMake for GLFW 3.4 new source files

Adds new GLFW 3.4 source files to the Linux build configuration:
- platform.c: Runtime platform selection infrastructure
- posix_thread.c, posix_module.c, posix_poll.c: POSIX API abstractions
- null_*.c: Null backend for headless/testing scenarios
- osmesa_context.c: Off-screen Mesa rendering support

These files are required for GLFW 3.4's modular architecture and
enhanced platform support.

Author: andrewfb

proj/cmake/platform_linux.cmake

@@ -10,16 +10,24 @@ list( APPEND SRC_SET_GLFW
 	${CINDER_SRC_DIR}/glfw/src/init.c
 	${CINDER_SRC_DIR}/glfw/src/input.c
 	${CINDER_SRC_DIR}/glfw/src/monitor.c
+	${CINDER_SRC_DIR}/glfw/src/platform.c
 	${CINDER_SRC_DIR}/glfw/src/window.c
 	${CINDER_SRC_DIR}/glfw/src/glx_context.c
 	${CINDER_SRC_DIR}/glfw/src/egl_context.c
+	${CINDER_SRC_DIR}/glfw/src/osmesa_context.c
 	${CINDER_SRC_DIR}/glfw/src/x11_init.c
 	${CINDER_SRC_DIR}/glfw/src/x11_monitor.c
 	${CINDER_SRC_DIR}/glfw/src/x11_window.c
 	${CINDER_SRC_DIR}/glfw/src/xkb_unicode.c
 	${CINDER_SRC_DIR}/glfw/src/linux_joystick.c
 	${CINDER_SRC_DIR}/glfw/src/posix_time.c
-	${CINDER_SRC_DIR}/glfw/src/posix_tls.c
+	${CINDER_SRC_DIR}/glfw/src/posix_thread.c
+	${CINDER_SRC_DIR}/glfw/src/posix_module.c
+	${CINDER_SRC_DIR}/glfw/src/posix_poll.c
+	${CINDER_SRC_DIR}/glfw/src/null_init.c
+	${CINDER_SRC_DIR}/glfw/src/null_joystick.c
+	${CINDER_SRC_DIR}/glfw/src/null_monitor.c
+	${CINDER_SRC_DIR}/glfw/src/null_window.c
 	${CINDER_SRC_DIR}/glfw/src/vulkan.c
 )