Detect whether cc (the linker) is gcc or clang.

Detect whether cc (the linker) is gcc or clang.

Use this information to drive which options are added to the `cc`
command line arguments.

As a drive-by, fix an english grammar mistake in a comment.

This is meant to be, in part, a more robust version of PR #17192.

Fix #17214.
(as for the `fail!`, I was following a philosophy of fail-fast, but a lowest-common-denominator `UnknownCcArgumentFormat` is reasonable too.  I'll switch to that.)