tests: use /usr/bin/env for bash.

tests/various/async.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -ex
 ../../yosys -q -o async_syn.v -r uut -p 'synth; rename uut syn' async.v
 ../../yosys -q -o async_prp.v -r uut -p 'prep; rename uut prp' async.v

tests/various/chparam.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 trap 'echo "ERROR in chparam.sh" >&2; exit 1' ERR
 

tests/various/logger_fail.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 fail() {
 	echo "$1" >&2

tests/various/smtlib2_module.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -ex
 ../../yosys -q -p 'read_verilog -formal smtlib2_module.v; prep; write_smt2 smtlib2_module.smt2'
 sed 's/; SMT-LIBv2 description generated by Yosys .*/; SMT-LIBv2 description generated by Yosys $VERSION/;s/  *$//' smtlib2_module.smt2 > smtlib2_module-filtered.smt2

tests/various/sv_implicit_ports.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 trap 'echo "ERROR in sv_implicit_ports.sh" >&2; exit 1' ERR
 

tests/various/svalways.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 trap 'echo "ERROR in svalways.sh" >&2; exit 1' ERR