regexp_split fails in empty match pattern

[HolyLow]

Bug description

The implementation of Re2RegexpSplit has a bug, that it might fail to split the string when the pattern is a empty string itself.

For example, in the function calling: regexp_split("abcd", "").
The expected result is {"", "a", "b", "c", "d", ""}, but the current implementation would throw error.

This testcase comes from presto https://github.com/prestodb/presto/blob/099bd42eba287b1ea25bf55404c7a18882e0f6d5/presto-main/src/test/java/com/facebook/presto/operator/scalar/AbstractTestRegexpFunctions.java#L231

System information

Velox System Info v0.0.2
Commit: b7ed8c7
CMake Version: 3.28.3
System: Linux-5.15.0-92-generic
Arch: x86_64
C++ Compiler: /usr/bin/c++
C++ Compiler Version: 11.4.0
C Compiler: /usr/bin/cc
C Compiler Version: 11.4.0
CMake Prefix Path: /usr/local;/usr;/;/usr/local/lib/python3.10/dist-packages/cmake/data;/usr/local;/usr/X11R6;/usr/pkg;/opt

Relevant logs