ci: add Jenkinsfile for running tests on macos

[jakubgs]

Also adds a Makefile to seaprate out the building of compiler.

[jakubgs]

Any idea what this is about?

[NimScript] exec: nim c  --styleCheck:usages --styleCheck:error --verbosity:0 --hints:off --skipParentCfg --skipUserCfg --outdir:build --nimcache:build/nimcache -f  --threads:on -r tests/all_tests
In file included from /Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/secp256k1.c:26:
In file included from /Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/field_impl.h:17:
In file included from /Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/field_5x52_impl.h:19:
/Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/field_5x52_asm_impl.h:282:3: error: invalid input constraint 'b' in asm
: "b"(b), "D"(r)
  ^
/Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/field_5x52_asm_impl.h:497:3: error: invalid input constraint 'D' in asm
: "D"(r)
  ^
In file included from /Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/secp256k1.c:27:
In file included from /Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/scalar_impl.h:24:
/Users/jenkins/workspace/nim-secp256k1_prs_PR-41/secp256k1/../secp256k1_wrapper/secp256k1/src/scalar_4x64_impl.h:384:7: error: unknown register name 'rax' in asm
    : "rax", "rdx", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "cc");
      ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
4 errors generated.

[arnetheduck]

Any idea what this is about?

this is the bug that I want to fix and need the ci for ;)

[jakubgs]

Would have been good to know about it in advance.