[dev.boringcrypto] cmd/compile: remove the awful boringcrypto kludge
CL 60271 introduced this “AwfulBoringCryptoKludge.”
iant approved that CL saying “As long as it stays out of master...”
Now that the rsa and ecdsa code uses boring.Cache, the
“boring unsafe.Pointer” fields are gone from the key structs, and this
code is no longer needed. So delete it.
With the kludge deleted, we are one step closer to being able to merge
dev.boringcrypto into master.
For #51940.
Change-Id: Ie549db14b0b699c306dded2a2163f18f31d45530
Reviewed-on: https://go-review.googlesource.com/c/go/+/395884 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>