Compilation fails with glm 0.9.9.3 (lp:#1804030)

[Original report](https://bugs.launchpad.net/bugs/1804030) created by **Victor W (vicw)**
```
When trying to compile the kicad git from source, it fails. This seems to
be due to the incremental update of glm 0.9.9.3 on archlinux.

When downgrading glm to 0.9.9.2, kicad git compiles without error.

The following errors and warnings occur when trying to compile using
Archlinux, glm 0.9.9.3 are:

===
-- KiCad install dir: </usr>
-- Check for installed GLEW -- found
-- Found GLM: /usr/include (found suitable version "0.9.9.3", minimum
required is "0.9.5.1")
-- Boost version: 1.68.0
-- Check for installed Python Interpreter -- found
-- Python module install path: lib/python2.7/site-packages
-- S3DSG version: 2.0.0
-- Boost version: 1.68.0
-- Found the following Boost libraries:
--   unit_test_framework
-- Boost version: 1.68.0
-- Found the following Boost libraries:
--   unit_test_framework
-- Boost version: 1.68.0
-- Found the following Boost libraries:
--   unit_test_framework
-- Configuring done
-- Generating done
-- Build files have been written to: /usr/src/pacman/kicad-git/src/kicad-
git/build
===
[ 30%] Built target version_header
[ 30%] Built target legacy_wx
[ 30%] Built target pcb_plot_lexer_source_files
[ 30%] Built target page_layout_lexer_source_files
[ 30%] Built target legacy_gal
[ 32%] Built target gal
[ 32%] Built target lib_table_lexer_source_files
[ 32%] Built target netlist_lexer_source_files
[ 43%] Built target common
[ 44%] Built target pcb_lexer_source_files
[ 44%] Building CXX object
common/CMakeFiles/pcbcommon.dir/__/pcbnew/pcb_base_frame.cpp.o
In file included from /usr/include/glm/ext/vector_bool2.hpp:5,
                 from /usr/include/glm/vec2.hpp:5,
                 from /usr/include/glm/glm.hpp:116,
                 from /usr/src//-git/src/kicad-
git/include/plugins/3dapi/xv3d_types.h:38,
                 from /usr/src//-git/src/kicad-
git/common/../3d-viewer/3d_viewer/../3d_canvas/../3d_rendering/3d_render_raytracing/accelerators/../shapes2D/../ray.h:33,
                 from /usr/src//-git/src/kicad-
git/common/../3d-viewer/3d_viewer/../3d_canvas/../3d_rendering/3d_render_raytracing/accelerators/../shapes2D/cbbox2d.h:33,
                 from /usr/src//-git/src/kicad-
git/common/../3d-viewer/3d_viewer/../3d_canvas/../3d_rendering/3d_render_raytracing/accelerators/../shapes2D/cobject2d.h:33,
                 from /usr/src//-git/src/kicad-
git/common/../3d-viewer/3d_viewer/../3d_canvas/../3d_rendering/3d_render_raytracing/accelerators/ccontainer2d.h:33,
                 from /usr/src//-git/src/kicad-
git/common/../3d-viewer/3d_viewer/../3d_canvas/cinfo3d_visu.h:34,
                 from /usr/src//-git/src/kicad-
git/common/../3d-viewer/3d_viewer/eda_3d_viewer.h:35,
                 from /usr/src//-git/src/kicad-
git/pcbnew/pcb_base_frame.cpp:42:
/usr/include/glm/detail/type_vec2.hpp:90:40: error: ‘constexpr const T&
glm::vec<2, T, Q>::operator[](glm::vec<2, T, Q>::length_type) const’ cannot
be overloaded with ‘constexpr T& glm::vec<2, T, Q>::operator[](glm::vec<2,
T, Q>::length_type) const’
   GLM_FUNC_DECL GLM_CONSTEXPR T const& operator[](length_type i) const;
                                        ^~~~~~~~
/usr/include/glm/detail/type_vec2.hpp:89:34: note: previous declaration
‘constexpr T& glm::vec<2, T, Q>::operator[](glm::vec<2, T, Q>::length_type)
const’
   GLM_FUNC_DECL GLM_CONSTEXPR T& operator[](length_type i);
                                  ^~~~~~~~

<snip>



4.18.16-arch1-1-ARCH
```
Original tags: glm

Story points: 12.0