Avoid some allocations in various println methods (#56308)

base/coreio.jl

@@ -1,8 +1,13 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
+print(x) = print(stdout, x)
+print(x1, x2) = print(stdout, x1, x2)
+println(x) = print(stdout, x, "\n")
+println(x1, x2) = print(stdout, x1, x2, "\n")
+
 print(xs...)   = print(stdout, xs...)
-println(xs...) = println(stdout, xs...)
-println(io::IO) = print(io, '\n')
+println(xs...) = print(stdout, xs..., "\n")  # fewer allocations than `println(stdout, xs...)`
+println(io::IO) = print(io, "\n")
 
 function show end
 function repr end