asahi,libagx,hk: don't set custom_target names

Per meson docs:

   This posarg is optional since 0.60.0. It defaults to the basename of the first output.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33682>

src/asahi/compiler/meson.build

@@ -45,7 +45,6 @@ libasahi_agx_files = files(
 )
 
 agx_nir_algebraic_c = custom_target(
-  'agx_nir_algebraic.c',
   input : 'agx_nir_algebraic.py',
   output : 'agx_nir_algebraic.c',
   command : [
@@ -56,7 +55,6 @@ agx_nir_algebraic_c = custom_target(
 )
 
 agx_opcodes_h = custom_target(
-  'agx_opcodes.h',
   input : ['agx_opcodes.h.py'],
   output : 'agx_opcodes.h',
   command : [prog_python, '@INPUT@'],
@@ -70,7 +68,6 @@ idep_agx_opcodes_h = declare_dependency(
 )
 
 agx_opcodes_c = custom_target(
-  'agx_opcodes.c',
   input : ['agx_opcodes.c.py'],
   output : 'agx_opcodes.c',
   command : [prog_python, '@INPUT@'],
@@ -79,7 +76,6 @@ agx_opcodes_c = custom_target(
 )
 
 agx_builder_h = custom_target(
-  'agx_builder.h',
   input : ['agx_builder.h.py'],
   output : 'agx_builder.h',
   command : [prog_python, '@INPUT@'],

src/asahi/genxml/meson.build

@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: MIT
 
 agx_pack = custom_target(
-  'agx_pack.h',
   input : ['gen_pack.py', 'cmdbuf.xml', 'agx_pack_header.h'],
   output : 'agx_pack.h',
   command : [prog_python, '@INPUT@'],

src/asahi/lib/meson.build

@@ -51,7 +51,6 @@ libasahi_decode_shared = shared_library(
 )
 
 libagx_shaders = custom_target(
-  'libagx_shaders',
   input : libagx_spv,
   output : ['libagx_shaders.h', 'libagx_shaders.c'],
   command : [prog_asahi_clc, libagx_spv, '@OUTPUT0@', '@OUTPUT1@'],

src/asahi/libagx/meson.build

@@ -17,7 +17,6 @@ libagx_shader_files = files(
 relative_dir = fs.relative_to(meson.global_source_root(), meson.global_build_root()) + '/'
 
 libagx_spv = custom_target(
-  'libagx.spv',
   input : libagx_shader_files,
   output : 'libagx.spv',
   command : [
@@ -34,7 +33,6 @@ libagx_spv = custom_target(
 )
 
 libagx = custom_target(
-  'libagx',
   input : libagx_spv,
   output : ['libagx.cpp', 'libagx.h'],
   command : [prog_vtn_bindgen2, libagx_spv, '@OUTPUT0@', '@OUTPUT1@'],

src/asahi/vulkan/meson.build

@@ -50,7 +50,6 @@ hk_files = files(
 )
 
 hk_entrypoints = custom_target(
-  'hk_entrypoints',
   input : [vk_entrypoints_gen, vk_api_xml],
   output : ['hk_entrypoints.h', 'hk_entrypoints.c'],
   command : [
@@ -111,7 +110,6 @@ if with_platform_windows
 endif
 
 asahi_icd = custom_target(
-  'asahi_icd',
   input : [vk_icd_gen, vk_api_xml],
   output : 'asahi_icd.@0@.json'.format(host_machine.cpu()),
   command : [
@@ -128,7 +126,6 @@ asahi_icd = custom_target(
 
 _dev_icdname = 'asahi_devenv_icd.@0@.json'.format(host_machine.cpu())
 custom_target(
-  'asahi_devenv_icd',
   input : [vk_icd_gen, vk_api_xml],
   output : _dev_icdname,
   command : [