mesa: add EXT_dsa indexed generic queries

Only GetPointerIndexedvEXT needs an implementation, the other functions are
aliases of existing functions.
13 jobs for !1416 with ext_dsa_misc in 18 minutes and 23 seconds (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Containers Build
passed #460370
debian

00:00:41

 
  Build+Test
passed #460379
meson-arm64

00:04:23

passed #460378
meson-armhf

00:02:47

passed #460372
meson-clang

00:08:11

passed #460376
meson-clover

00:09:05

passed #460380
meson-i386

00:03:37

passed #460375
meson-main

00:05:09

passed #460371
meson-swr-glvnd

00:08:26

passed #460377
meson-vulkan

00:05:02

passed #460382
scons-llvm

00:04:01

passed #460381
scons-nollvm

00:08:38

passed #460373
scons-swr

00:06:02

passed #460374
scons-win64

00:06:27