feat(liboqs): allow setting OQS_PERMIT_UNSUPPORTED_ARCHITECTURE CMake option via environment variable (#203)

fix #202

This allows to set the `OQS_PERMIT_UNSUPOPORTED_ARCHITECTURE` CMake
option via an environment variable.

Author: wucke13

oqs-sys/build.rs

@@ -100,6 +100,12 @@ fn build_from_source() -> PathBuf {
     } else {
         config.define("OQS_USE_OPENSSL", "No");
     }
+
+    let permit_unsupported = "OQS_PERMIT_UNSUPPORTED_ARCHITECTURE";
+    if let Ok(str) = std::env::var(permit_unsupported) {
+        config.define(permit_unsupported, str);
+    }
+
     let outdir = config.build_target("oqs").build();
 
     // lib is put into $outdir/build/lib