[llvm] [X86] Resolve FIXME: Add FPCW as a rounding control register (PR #82452)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

Agreed with @topperc. The origion code was to solve #59305. The problem seems exist on X87 too. You may modify `llvm/test/CodeGen/X86/pr59305.ll` by adding `; RUN: llc -mtriple=i686-pc-linux < %s | FileCheck %s`

https://github.com/llvm/llvm-project/pull/82452