extensions/khr: Add VK_KHR_performance_query

[MarijnS95]

CC @wolfiestyle

[wolfiestyle]

Couldn't test locally. patch doesn't work applied to 0.37.2, and trying to use HEAD w/patch breaks other deps.
The error:

$ cargo check
    Checking ash v0.37.2+1.3.238 (/home/wolfie/progs/rust/vktest/ash/ash)
error[E0599]: no associated item named `NAME` found for struct `KhrPerformanceQueryFn` in the current scope
    --> ash/ash/src/extensions/khr/performance_query.rs:107:64
     |
107  |     pub const NAME: &'static CStr = vk::KhrPerformanceQueryFn::NAME;
     |                                                                ^^^^ associated item not found in `KhrPerformanceQueryFn`
     |
    ::: ash/ash/src/vk/extensions.rs:7017:1
     |
7017 | pub struct KhrPerformanceQueryFn {
     | -------------------------------- associated item `NAME` not found for this struct

[MarijnS95]

@wolfiestyle I'll address that after merging and backporting this to the 0.37-stable branch, and for the time being you can replace this associated constant with:

    #[inline]
    pub const fn name() -> &'static CStr {
        vk::KhrPerformanceQueryFn::name()
    }