Merge pull request #208098 from alyssais/simdjson-powerpc

simdjson: fix build on powerpc64

pkgs/development/libraries/simdjson/default.nix

···
 
   cmakeFlags = [
     "-DSIMDJSON_DEVELOPER_MODE=OFF"
-  ] ++ lib.optional stdenv.hostPlatform.isStatic "-DBUILD_SHARED_LIBS=OFF";
+  ] ++ lib.optionals stdenv.hostPlatform.isStatic [
+    "-DBUILD_SHARED_LIBS=OFF"
+  ] ++ lib.optionals (with stdenv.hostPlatform; isPower && isBigEndian) [
+    # Assume required CPU features are available, since otherwise we
+    # just get a failed build.
+    "-DCMAKE_CXX_FLAGS=-mpower8-vector"
+  ];
 
   meta = with lib; {
     homepage = "https://simdjson.org/";