cf69f9e220
fix CTFE/Miri simd_insert/extract on array-style repr(simd) types The changed test would previously fail since `place_index` would just return the only field of `f32x4`, i.e., the array -- rather than *indexing into* the array which is what we have to do. The new helper methods will also be needed for https://github.com/rust-lang/miri/issues/1912. r? ``````@oli-obk``````