two readline/tests/libedit tests fail

### HHVM Version

swalk@lab-7:~/extra/play.042319a/hhvm$ hphp/hhvm/hhvm --version
HipHop VM 4.2.0-dev (rel)
Compiler: heads/master-0-g9067e10949b8a0fb6db2a9c4f42ea749ab694a32
Repo schema: 239f9a363ad7e2267c99267e39ab71aea37d5b4e

swalk@dellx3:~/play.042319a/hhvm$ hphp/hhvm/hhvm --version
HipHop VM 4.2.0-dev (rel)
Compiler: heads/master-0-g9067e10949b8a0fb6db2a9c4f42ea749ab694a32
Repo schema: c6c673f3215d48a359319122fce7120b411437b7

### Operating System and Version

Seen on two machines, both running Ubuntu 16.04

swalk@dellx3:~/play.042319a/hhvm$ uname -a
Linux dellx3 4.4.0-57-generic #78-Ubuntu SMP Fri Dec 9 23:50:32 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

swalk@lab-7:~/extra/play.042319a/hhvm$ uname -a
Linux lab-7 4.4.0-138-generic #164-Ubuntu SMP Tue Oct 2 17:15:48 UTC 2018 aarch64 aarch64 aarch64 GNU/Linux

### Standalone code, or other way to reproduce the problem

hphp/test/run -v -m interp
hphp/test/run -v -m interp -r
hphp/test/run -v -m jit -a '-vEval.JitPGO=0'
hphp/test/run -v -m jit -r -a '-vEval.JitPGO=0'
hphp/test/run -v -m jit -a '-vEval.JitPGO=1'
hphp/test/run -v -m jit -r -a '-vEval.JitPGO=1'

### Actual result

Post-processed report below. Columns line up with option sets above.

hphp/test/zend/good/ext/readline/tests/libedit_info_001.php | F | F | F | F | F | F |
hphp/test/zend/good/ext/readline/tests/libedit_write_history_001.php | F | F | F | F | F | F |

### Expected result

Pass

Replaying commands by hand shows issue.

swalk@dellx3:~/play.042319a/hhvm$ ./hphp/hhvm/hhvm -c /home/swalk/play.042319a/hhvm/hphp/test/zend/config.ini -vEval.EnableArgsInBacktraces=true -vEval.EnableIntrinsicsExtension=true -vEval.HHIRInliningIgnoreHints=false -vRepo.Local.Mode=-- -vRepo.Central.Path=/home/swalk/play.042319a/hhvm/hphp/hhvm/verify.hhbc -vEval.Jit=true -vEval.ProfileHWEnable=false -vEval.HackCompilerExtractPath='/home/swalk/play.042319a/hhvm/hphp/hhvm/hackc_%{schema}' -vEval.EmbeddedDataExtractPath='/home/swalk/play.042319a/hhvm/hphp/hhvm/hhvm_%{type}_%{buildid}' -vResourceLimit.CoreFileSize=0 --file 'hphp/test/zend/good/ext/readline/tests/libedit_info_001.php'
array(6) {
["line_buffer"]=>
string(0) ""
["point"]=>
int(0)
["end"]=>
int(0)
["library_version"]=>
string(16) "EditLine wrapper"
["readline_name"]=>
string(0) ""
["attempted_completion_over"]=>
int(0)
}

Fatal error: Uncaught exception 'RuntimeException' with message 'readline_info() expects parameter 1 to be string, integer given' in /home/swalk/play.042319a/hhvm/hphp/test/zend/good/ext/readline/tests/libedit_info_001.php:4
Stack trace:
#0 /home/swalk/play.042319a/hhvm/hphp/test/zend/good/ext/readline/tests/libedit_info_001.php(4): readline_info()
#1 {main}