[cmake] Generator expression test during configure doesn't work.

[kasper93]

Describe the bug
Building https://github.com/google/shaderc doesn't work because there are issues with install support in meson. But I don't need install, so I disabled it. Unfortunately this doesn't work too.

To Reproduce
Try to disable glslang install while building shaderc. Example wrap (source)

project('shaderc', 'cpp', version: '2024.1')

python = find_program('python3')
run_command(python, '../shaderc_cmake/utils/git-sync-deps', check: true)

cmake = import('cmake')
opts = cmake.subproject_options()
opts.add_cmake_defines({
    'CMAKE_MSVC_RUNTIME_LIBRARY': 'MultiThreaded',
    'CMAKE_POLICY_DEFAULT_CMP0091': 'NEW',
    'SHADERC_SKIP_INSTALL': 'ON',
    'SHADERC_SKIP_TESTS': 'ON',
    'SHADERC_SKIP_EXAMPLES': 'ON',
    'SHADERC_SKIP_COPYRIGHT_CHECK': 'ON'
})
shaderc_proj = cmake.subproject('shaderc_cmake', options: opts)
shaderc_dep = declare_dependency(dependencies: [
    shaderc_proj.dependency('shaderc'),
    shaderc_proj.dependency('shaderc_util'),
    shaderc_proj.dependency('SPIRV'),
    shaderc_proj.dependency('SPIRV-Tools-static'),
    shaderc_proj.dependency('SPIRV-Tools-opt'),
    shaderc_proj.dependency('glslang'),
    shaderc_proj.dependency('GenericCodeGen'),
    shaderc_proj.dependency('MachineIndependent'),
])
meson.override_dependency('shaderc', shaderc_dep)

The issue is simple, for this expression, when SKIP_GLSLANG_INSTALL is set to ON.
set(GLSLANG_ENABLE_INSTALL $<NOT:${SKIP_GLSLANG_INSTALL}>)

The following expression will evaluate truthfully, while it shouldn't.
if (GLSLANG_ENABLE_INSTALL)

I've sent workaround to shaderc google/shaderc#1415 but not sure they will want to workaround meson issues, although it is small change.

Expected behavior
It works.

system parameters

• Is this a cross build or just a plain native build (for the same computer)?
• Windows 11
• Python 3.12
• meson 1.4