Decide inline-worthiness based on a more nuanced cost model

Author: timholy

base/boot.jl

@@ -382,4 +382,6 @@ show(a::ANY) = show(STDOUT, a)
 print(a::ANY...) = print(STDOUT, a...)
 println(a::ANY...) = println(STDOUT, a...)
 
+eval(Main, :(const hacklog = Array{Any,1}(0)))
+
 ccall(:jl_set_istopmod, Void, (Bool,), true)