Add missing WEAK to android halide_opengl_get_proc_address()
Add missing WEAK to android halide_opengl_get_proc_address()

HelloAndroidGL won’t build right now, as the LLVM linker requires all
runtime module functions beginning with “halide_” to be weak, and all
other platform versions of this function are also weak


Former-commit-id: 1975d6f7d04503d0f546caaa4353bac557c809b4
Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide