M1 support doesn't work

Steps to reproduce:
1) Install re2 in the system (brew install re2)
2) Prepare dub.json (as code.dlang version was not updated since last code changes):
```json
"dependencies": {
"re2d": {"version": "0e11a027e85fd4892829e23dd61dc417fe292ecb", "repository": "git+https://github.com/google/re2d.git"}
},
"libs": ["re2", "c++"],
```
3) dub build

It will show linkage error:
```bash
Undefined symbols for architecture arm64:
"bool re2::re2_internal::Parse(char const*, unsigned long, re2::StringPiece*)", referenced from:
bool re2::RE2::Arg::DoParse3ary(char const*, unsigned long, void const*) in re2test.o
"re2::RE2::FullMatchN(re2::StringPiece const&, re2::RE2 const&, re2::RE2::Arg const* const*, int)", referenced from:
__D4re2d3re23RE2__T5ApplyX62_ZN3re23RE210FullMatchNERKNS_11StringPieceERKS0_PKPKNS0_3ArgEiTAyaTPSQDq11stringpiece11StringPieceZQEeFNaNbNiQBuKxSQFkQFiQFhQCfZb in re2test.o
"re2::RE2::RE2(re2::StringPiece const&)", referenced from:
__D4re2d3re23RE26__ctorMFNaNbNcNiAyaZSQBjQBhQBg in libre2d.a[4](re2d.re2.o)
ld: symbol(s) not found for architecture arm64
```