GL: drop symbols mangling support

SCons and Meson have never supported that feature, and Autotools was
deleted over 6 months ago and no-one complained yet, so it's pretty
obvious nobody cares about it.

Fixes: 95aefc94 ("Delete autotools")
Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Acked-by: Dylan Baker <dylan@pnwbakers.com>
49 jobs for !2295 with unmangle in 2 minutes and 35 seconds (queued for 6 seconds)
detached
Status Job ID Name Coverage
  Containers
passed #728902
debian-10

00:00:25

passed #728903
debian-9

00:00:20

passed #728901
lava-container:arm64

00:01:51

passed #728900
lava-container:armhf

00:01:32

passed #728904
aarch64
test-container:arm64

00:00:19

 
  Build
canceled #728906
lava-build:arm64

canceled #728905
lava-build:armhf

00:00:28

canceled #728909
meson-arm64

00:00:43

canceled #728908
meson-armhf

00:00:55

canceled #728911
meson-clang

canceled #728914
meson-clover

canceled #728915
meson-clover-old-llvm

00:00:58

canceled #728917
meson-i386

canceled #728907
meson-main

00:00:56

canceled #728910
meson-swr-glvnd

00:00:02

canceled #728916
meson-vulkan

canceled #728918
scons

canceled #728919
scons-old-llvm

canceled #728912
scons-swr

canceled #728913
scons-win64

 
  Test
canceled #728944
db410c
arm64_a306_gles2 1/4

canceled #728945
db410c
arm64_a306_gles2 2/4

canceled #728946
db410c
arm64_a306_gles2 3/4

canceled #728947
db410c
arm64_a306_gles2 4/4

canceled #728933
mesa-cheza
arm64_a630_gles2

canceled #728934
mesa-cheza
arm64_a630_gles31 1/4

canceled #728935
mesa-cheza
arm64_a630_gles31 2/4

canceled #728936
mesa-cheza
arm64_a630_gles31 3/4

canceled #728937
mesa-cheza
arm64_a630_gles31 4/4

canceled #728938
mesa-cheza
arm64_a630_gles3 1/6

canceled #728939
mesa-cheza
arm64_a630_gles3 2/6

canceled #728940
mesa-cheza
arm64_a630_gles3 3/6

canceled #728941
mesa-cheza
arm64_a630_gles3 4/6

canceled #728942
mesa-cheza
arm64_a630_gles3 5/6

canceled #728943
mesa-cheza
arm64_a630_gles3 6/6

canceled #728923
lava-meson-gxl-s905x-libretech-cc
lima-test:arm64

canceled #728922
lava-sun8i-h3-libretech-all-h3-cc
lima-test:armhf

canceled #728920
lava-rk3288-veyron-jaq
panfrost-t760-test:armhf

canceled #728921
lava-rk3399-gru-kevin
panfrost-t860-test:arm64

canceled #728924
test-llvmpipe-gles2 1/4

canceled #728925
test-llvmpipe-gles2 2/4

canceled #728926
test-llvmpipe-gles2 3/4

canceled #728927
test-llvmpipe-gles2 4/4

canceled #728928
test-softpipe-gles2 1/4

canceled #728929
test-softpipe-gles2 2/4

canceled #728930
test-softpipe-gles2 3/4

canceled #728931
test-softpipe-gles2 4/4

canceled #728932
test-softpipe-gles3-limited

 
  External
canceled continuous-integration/appveyor/branch