Revert "unify prod(::Tuple{Vararg{Int}}) with a single method (#57628)" (#57894)

This reverts commit 3d62893.

See
#57628 (comment)
for array indexing regressions

Author: topolarity

base/tuple.jl

@@ -649,15 +649,12 @@ reverse(t::Tuple) = revargs(t...)
 
 ## specialized reduction ##
 
-# used in bootstrapping
-function prod(x::Tuple{Vararg{Int}})
-    @_terminates_locally_meta
-    r = 1
-    for y in x
-        r *= y
-    end
-    r
-end
+prod(x::Tuple{}) = 1
+# This is consistent with the regular prod because there is no need for size promotion
+# if all elements in the tuple are of system size.
+# It is defined here separately in order to support bootstrap, because it's needed earlier
+# than the general prod definition is available.
+prod(x::Tuple{Int, Vararg{Int}}) = *(x...)
 
 # a version of `in` esp. for NamedTuple, to make it pure, and not compiled for each tuple length
 function sym_in(x::Symbol, itr::Tuple{Vararg{Symbol}})