Remove unused members from ES build.

src/Magnum/Implementation/TextureState.h

@@ -46,10 +46,14 @@ struct TextureState {
     void(AbstractTexture::*parameterivImplementation)(GLenum, const GLint*);
     #endif
     void(AbstractTexture::*parameterfvImplementation)(GLenum, const GLfloat*);
+    #ifndef MAGNUM_TARGET_GLES
     void(AbstractTexture::*parameterIuivImplementation)(GLenum, const GLuint*);
     void(AbstractTexture::*parameterIivImplementation)(GLenum, const GLint*);
+    #endif
     void(AbstractTexture::*setMaxAnisotropyImplementation)(GLfloat);
+    #ifndef MAGNUM_TARGET_GLES
     void(AbstractTexture::*getLevelParameterivImplementation)(GLenum, GLint, GLenum, GLint*);
+    #endif
     void(AbstractTexture::*mipmapImplementation)();
     #ifndef MAGNUM_TARGET_GLES
     void(AbstractTexture::*storage1DImplementation)(GLenum, GLsizei, TextureFormat, const Math::Vector<1, GLsizei>&);