fascistic commit r084e2284c700 busybox/scripts/gen_build_files.sh

[Douglas Mencken]

This commit declares "gen_build_files.sh" as the one that "uses
bashism", and "document it".
But what is the real result of this commit? It is:
    make: /root/build-farm/busybox-1969-g084e228.srcpkg/scripts/gen_build_files.sh:
Command not found
    make: *** [gen_build_files] Error 127
Because
    -#!/bin/sh
    +#!/bin/bash
So now it is not possible to build busybox having only busybox shell
(ash) and not bash.