Revert "Add hash function for compatibility with sh/bash"

This reverts commit dbd228cc75.

CHANGELOG.md

@@ -68,7 +68,6 @@ fish 3.0 is a major release which brings with it both improvements in functional
 - `test` and `[` now support floating point values in numeric comparisons.
 - Autosuggestions try to avoid arguments that are already present in the command line.
 - Variables may be used inside commands (#154).
-- A `hash` function has been added for compatibiility with `sh` and `bash`
 - `while` sets `$status` to a more useful value (#4982)
 
 ## Other significant changes

share/functions/hash.fish

@@ -1,10 +0,0 @@
-# Under (ba)sh, `hash` acts like a caching `which`, but it doesn't print
-# anything on success. Its return code is used to determine success vs failure.
-function hash
-	if not set -q argv[1]
-		echo "Usage: hash FILE" >&2
-		return 1
-	end
-	which $argv[1] 2>/dev/null 1>/dev/null
-	or printf "%s: not found!\n" $argv[1] >&2 && return 2 # ENOENT
-end