semver: deprecate semver.Max

There are a number of calls to semver.Max in the wild, so let's not
delete it yet.

For golang/go#32700

Change-Id: I515b05f174195d1b82a931b92e21b83c370ef7c7
Reviewed-on: https://go-review.googlesource.com/c/mod/+/269357
Trust: Jay Conrod <[email protected]>
Run-TryBot: Jay Conrod <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>

Author: Jay Conrod

semver/semver.go

@@ -138,6 +138,9 @@ func Compare(v, w string) int {
 
 // Max canonicalizes its arguments and then returns the version string
 // that compares greater.
+//
+// Deprecated: use Compare instead. In most cases, returning a canonicalized
+// version is not expected or desired.
 func Max(v, w string) string {
 	v = Canonical(v)
 	w = Canonical(w)