[compiler-rt] Enable generic TF builtins for i386 (PR #200816)

[Adrian Ratiu via llvm-commits]

10ne1 wrote:

Thank you @arichardson It's done. 

It also makes sense to split into 2 PRs because they are 2 independent (though related) fixes.

Please also see https://github.com/llvm/llvm-project/pull/201078.

https://github.com/llvm/llvm-project/pull/200816