Split out the code that computes the initial inline "hairyness" budget
for a function so that it can be reused (in a later patch). This is a
pure refactoring; no change in compiler functionality.
Change-Id: I9b1b7b10a7c480559b837492b10eb08771b7a145
Reviewed-on: https://go-review.googlesource.com/c/go/+/514795
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Keith Randall <khr@golang.org>