M1 support doesn't work

[cyrusmsk]

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):

 "dependencies": {
        "re2d": {"version": "0e11a027e85fd4892829e23dd61dc417fe292ecb", "repository": "git+https://github.com/google/re2d.git"}
    },
    "libs": ["re2", "c++"],

3. dub build

It will show linkage error:

Undefined symbols for architecture arm64:
  "bool re2::re2_internal::Parse<re2::StringPiece>(char const*, unsigned long, re2::StringPiece*)", referenced from:
      bool re2::RE2::Arg::DoParse3ary<re2::StringPiece>(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