crypto/x509: hardcode RSA PSS parameters rather than generating them
Rather than generating the three possible RSA PSS parameters each time
they are needed just hardcode them and pick the required one based on
the hash function.
Fixes #41407
Change-Id: Id43bdaf40b3ca82c4c04c6588e3b643f63107657
Reviewed-on: https://go-review.googlesource.com/c/go/+/258037
Run-TryBot: Roland Shoemaker <roland@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Roland Shoemaker <roland@golang.org> Reviewed-by: Filippo Valsorda <filippo@golang.org>