Rollup merge of rust-lang#78666 - sasurau4:fix/shellcheck-error, r=jyn514

Fix shellcheck error

## Overview

Helps with rust-lang#77290

This pr fix only errors of shellcheck, the result of `git ls-files '*.sh' | xargs shellcheck --severity=error`.

Fixing error are following.

- https://github.com/koalaman/shellcheck/wiki/SC2148
- https://github.com/koalaman/shellcheck/wiki/SC1008

Disable error following.
- https://github.com/koalaman/shellcheck/wiki/SC2068

Author: JohnTitor

scripts/cargo.sh

@@ -10,7 +10,7 @@ cmd=$1
 shift || true
 
 if [[ "$cmd" = "jit" ]]; then
-cargo +${TOOLCHAIN} rustc $@ -- --jit
+cargo +${TOOLCHAIN} rustc "$@" -- --jit
 else
-cargo +${TOOLCHAIN} $cmd $@
+cargo +${TOOLCHAIN} $cmd "$@"
 fi

scripts/config.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 set -e
 
 unamestr=`uname`

test.sh

@@ -3,13 +3,13 @@ set -e
 
 export RUSTFLAGS="-Zrun_dsymutil=no"
 
-./build.sh --without-sysroot $@
+./build.sh --without-sysroot "$@"
 
 rm -r target/out || true
 
 scripts/tests.sh no_sysroot
 
-./build.sh $@
+./build.sh "$@"
 
 scripts/tests.sh base_sysroot
 scripts/tests.sh extended_sysroot