gstallocator: Make alloc function take GstAllocationParams by const

The param argument passed to this function does not need to be modified.
Add const to enforce this at compile-time and emit a proper signature in
G-IR.
36 jobs for !729 with parameter-const-correctness in 56 seconds (queued for 4 seconds)
latest detached
Status Job ID Name Coverage
  Build Docker
passed #6649632
alpine amd64 manifest builder docker

00:00:37

passed #6649631
android docker

00:00:23

passed #6649630
cerbero fedora amd64 docker

00:00:37

passed #6649629
fedora amd64 docker

00:00:38

passed #6649633
gst-indent amd64 docker

00:00:09

 
  Preparation
passed #6649636
check allow-edit

00:00:14

passed #6649635
gst indent

00:00:17

manual #6649634
manual
manifest
 
  Build
created #6649645
gstreamer
build cerbero cross-android universal
created #6649649
gst-ios-13.2
build cerbero cross-ios universal
created #6649646
gstreamer
build cerbero cross win32
created #6649647
gstreamer
build cerbero cross win64
created #6649644
gstreamer
build cerbero fedora x86_64
created #6649648
gst-macos-10.15
build cerbero macos x86_64
created #6649650
docker windows gstreamer-windows 1809
build cerbero msvc x86_64
created #6649640
build clang fedora x86_64
created #6649643
docker windows 1809 allowed to fail manual
build msys2
created #6649637
build nodebug fedora x86_64
created #6649638
build static fedora x86_64
created #6649639
build static nodebug fedora x86_64
created #6649641
docker windows 1809
build vs2017 amd64
created #6649642
docker windows 1809
build vs2017 x86
 
  Test
created #6649651
gstreamer
check fedora
created #6649652
gstreamer
integration testsuites fedora 1/4
created #6649653
gstreamer
integration testsuites fedora 2/4
created #6649654
gstreamer
integration testsuites fedora 3/4
created #6649655
gstreamer
integration testsuites fedora 4/4
created #6649660
gstreamer
valgrind bad
created #6649657
gstreamer
valgrind base
created #6649656
gstreamer
valgrind core
created #6649661
gstreamer
valgrind ges
created #6649658
gstreamer
valgrind good
created #6649659
gstreamer
valgrind ugly
 
  Integrate
created #6649662
cross-android universal examples
created #6649664
gst-ios-13.2
cross-ios universal examples
created #6649663
documentation