Building on aarch64 MacOS / with LLVM 21

[wolfgangwalther]

While packaging orioledb in Nixpkgs I failed to build orioledb/postgres on MacOS (aarch64) with:

llvmjit_wrap.cpp:60:18: error: no matching constructor for initialization of 'llvm::orc::RTDyldObjectLinkingLayer'
   60 |         return wrap(new llvm::orc::RTDyldObjectLinkingLayer(
      |                         ^
   61 |                 *unwrap(ES), [] { return std::make_unique<llvm::backport::SectionMemoryManager>(nullptr, true); }));
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/k71q2lxpdih3znara5x88saz881k49gs-llvm-21.1.8-dev/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h:58:3: note: candidate constructor not viable: no known conversion from '(lambda at llvmjit_wrap.cpp:61:16)' to 'GetMemoryManagerFunction' (aka 'unique_function<std::unique_ptr<RuntimeDyld::MemoryManager> (const MemoryBuffer &)>') for 2nd argument
   58 |   RTDyldObjectLinkingLayer(ExecutionSession &ES,
      |   ^
   59 |                            GetMemoryManagerFunction GetMemoryManager);
      |                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/k71q2lxpdih3znara5x88saz881k49gs-llvm-21.1.8-dev/include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h:37:16: note: candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 2 were provided
   37 | class LLVM_ABI RTDyldObjectLinkingLayer
      |                ^~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
make[2]: *** [<builtin>: llvmjit_wrap.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[2]: Leaving directory '/nix/var/nix/builds/nix-51456-598611611/source/src/backend/jit/llvm'
make[1]: *** [Makefile:42: all-backend/jit/llvm-recurse] Error 2
make[1]: Leaving directory '/nix/var/nix/builds/nix-51456-598611611/source/src'
make: *** [GNUmakefile:16: world-src-recurse] Error 2

It seems like the patch in postgres/postgres@0dceba2 should fix this.