[CostModel][X86] Improve extract/insert element costs (PR43605)

[CostModel][X86] Improve extract/insert element costs (PR43605)

This tries to improve the accuracy of extract/insert element costs by accounting for subvector extraction/insertion for >128-bit vectors and the shuffling of elements to/from the 0'th index.

It also adds INSERTPS for f32 types and PINSR/PEXTR costs for integer types (at the moment we assume the same cost as MOVD/MOVQ - which isn't always true).

Differential Revision: https://reviews.llvm.org/D74976