Rollup merge of #45961 - dereckson:unix-agnosticity-ci, r=Mark-Simulacrum

Use #!/usr/bin/env as shebang for Bash scripts

On some systems, the bash command could be available in another
directory than /bin. As such, to offer an env shebang is more
convenient.

This make sense even for docker scripts, as you can use Docker
on FreeBSD or SmartOS for example.

Author: GuillaumeGomez

src/ci/docker/cross/build-arm-musl.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/cross/build-rumprun.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/cross/install-x86_64-redox.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/cross2/build-fuchsia-toolchain.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/cross2/build-solaris-toolchain.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/disabled/dist-x86_64-dragonfly/build-toolchain.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/disabled/dist-x86_64-haiku/build-toolchain.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/disabled/dist-x86_64-haiku/fetch-packages.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/disabled/wasm32-exp/node.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.

src/ci/docker/dist-aarch64-linux/build-toolchains.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 # file at the top-level directory of this distribution and at
 # http://rust-lang.org/COPYRIGHT.