I can confirm that the issue is fixed with the initial fix.

glxinfo | grep Mesa
    client glx vendor string: Mesa Project and SGI
    OpenGL core profile version string: 4.5 (Core Profile) Mesa 18.3.0-devel
(git-fa52ff856d)
    OpenGL version string: 4.5 (Compatibility Profile) Mesa 18.3.0-devel
(git-fa52ff856d)
    OpenGL ES profile version string: OpenGL ES 3.2 Mesa 18.3.0-devel
(git-fa52ff856d)

glxinfo | grep LLVM
    Device: AMD PITCAIRN (DRM 2.50.0, 4.18.12-arch1-1-ARCH, LLVM 8.0.0)
(0x6818)
    OpenGL renderer string: AMD PITCAIRN (DRM 2.50.0, 4.18.12-arch1-1-ARCH,
LLVM 8.0.0)

LLVM was built from commit c179d7b.