net/rpc: use reflect.TypeFor for known types

For #60088

Change-Id: I56586b68d5e38a46560f4ced19214f1d2db2850e
Reviewed-on: https://go-review.googlesource.com/c/go/+/514995
Run-TryBot: Ian Lance Taylor <[email protected]>
Run-TryBot: Ian Lance Taylor <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Reviewed-by: David Chase <[email protected]>
Reviewed-by: Rob Pike <[email protected]>
Auto-Submit: Ian Lance Taylor <[email protected]>

Author: ianlancetaylor

src/net/rpc/server.go

@@ -146,9 +146,8 @@ const (
 	DefaultDebugPath = "/debug/rpc"
 )
 
-// Precompute the reflect type for error. Can't use error directly
-// because Typeof takes an empty interface value. This is annoying.
-var typeOfError = reflect.TypeOf((*error)(nil)).Elem()
+// Precompute the reflect type for error.
+var typeOfError = reflect.TypeFor[error]()
 
 type methodType struct {
 	sync.Mutex // protects counters