feat(const_eval): impl. log

CHANGELOG.md

@@ -78,6 +78,7 @@ Bottom level categories:
         - `fract`
         - `fma`
         - `inverseSqrt`
+        - `log`
 - Eager release of GPU resources comes from device.trackers. By @bradwerth in [#5075](https://github.com/gfx-rs/wgpu/pull/5075)
 - `wgpu-types`'s `trace` and `replay` features have been replaced by the `serde` feature. By @KirmesBude in [#5149](https://github.com/gfx-rs/wgpu/pull/5149)
 - `wgpu-core`'s `serial-pass` feature has been removed. Use `serde` instead. By @KirmesBude in [#5149](https://github.com/gfx-rs/wgpu/pull/5149)

naga/src/proc/constant_evaluator.rs

@@ -934,6 +934,9 @@ impl<'a> ConstantEvaluator<'a> {
             crate::MathFunction::InverseSqrt => {
                 component_wise_float!(self, span, [arg], |e| { Ok([1. / e.sqrt()]) })
             }
+            crate::MathFunction::Log => {
+                component_wise_float!(self, span, [arg], |e| { Ok([e.ln()]) })
+            }
             crate::MathFunction::Round => {
                 // TODO: Use `f{32,64}.round_ties_even()` when available on stable. This polyfill
                 // is shamelessly [~~stolen from~~ inspired by `ndarray-image`][polyfill source],