OpenMP threading support for Windows

[termoshtt]

Runtime error of STATUS_DLL_NOT_FOUND occurs for iomp targets:

##[warning]   Compiling intel-mkl-sys v0.2.0-alpha.0 (D:\a\intel-mkl-src\intel-mkl-src\intel-mkl-sys)
    Finished test [unoptimized + debuginfo] target(s) in 3m 08s
     Running target\debug\deps\intel_mkl_sys-d6a75171bad72c77.exe
error: test failed, to rerun pass '--lib'
##[error]test failed, to rerun pass '--lib'
Caused by:
  process didn't exit successfully: `d:\a\intel-mkl-src\intel-mkl-src\target\debug\deps\intel_mkl_sys-d6a75171bad72c77.exe` (exit code: 0xc0000135, STATUS_DLL_NOT_FOUND)
##[error]The process 'C:\Rust\.cargo\bin\cargo.exe' failed with exit code 3221225781

#48 (comment)

[ChingChuan-Chen]

@termoshtt We can close this issue now.

[termoshtt]

This has been fixed and confirmed in Windows instance of GitHub Actions.