LLVM: Activate typed pointers through the API instead of a global opt…

…ion. (#51840)

This allows other users of LLVM to use opaque pointers with their
contexts.

Co-authored-by: Jameson Nash <vtjnash@gmail.com>

src/codegen.cpp

@@ -9196,17 +9196,12 @@ extern "C" void jl_init_llvm(void)
  if (clopt && clopt->getNumOccurrences() == 0)
  cl::ProvidePositionalOption(clopt, "4", 1);
 
-#if JL_LLVM_VERSION >= 150000
+ // we want the opaque-pointers to be opt-in, per LLVMContext, for this release
+ // so change the default value back to pre-14.x, without changing the NumOccurrences flag for it
  clopt = llvmopts.lookup("opaque-pointers");
  if (clopt && clopt->getNumOccurrences() == 0) {
-#ifdef JL_LLVM_OPAQUE_POINTERS
- cl::ProvidePositionalOption(clopt, "true", 1);
-#else
- cl::ProvidePositionalOption(clopt, "false", 1);
-#endif
+ clopt->addOccurrence(1, clopt->ArgStr, "false", true);
  }
-#endif
-
  jl_ExecutionEngine = new JuliaOJIT();
 
  bool jl_using_gdb_jitevents = false;

src/jitlayers.cpp

@@ -1329,6 +1329,12 @@ JuliaOJIT::JuliaOJIT()
  ExternalJD(ES.createBareJITDylib("JuliaExternal")),
  ContextPool([](){
  auto ctx = std::make_unique<LLVMContext>();
+ if (!ctx->hasSetOpaquePointersValue())
+#ifndef JL_LLVM_OPAQUE_POINTERS
+ ctx->setOpaquePointers(false);
+#else
+ ctx->setOpaquePointers(true);
+#endif
  return orc::ThreadSafeContext(std::move(ctx));
  }),
 #ifdef JL_USE_JITLINK