shader: require GPU_shaders5 when gs_num_invocations is given
Fixes a compile error:
vrend_compile_shader: context error reported 7 "deqp-gles31" Illegal shader 0
shader failed to compile
0:3(33): error: GL_ARB_gpu_shader5 invocations qualifier specified
1: #version 150
2: #extension GL_ARB_shader_bit_encoding : require
3: layout(triangles, invocations = 2) in;
4: layout(points, max_vertices = 3) out;
...
Edited by Gert Wollny