Fix top of LLVM, and remove upper limit of LLVM version from CMakeLists. (#8568)

* Fix top of LLVM.

* No upper limit to LLVM in CMakeLists.

* Update CMakeLists.txt

Co-authored-by: Alex Reinking <[email protected]>

---------

Co-authored-by: Alex Reinking <[email protected]>

Author: mcourteaux

CMakeLists.txt

@@ -196,7 +196,7 @@ option(THREADS_PREFER_PTHREAD_FLAG "When enabled, prefer to use the -pthread fla
 find_package(Threads REQUIRED)
 
 ## LLVM
-find_package(Halide_LLVM 18...20 REQUIRED
+find_package(Halide_LLVM 18...99 REQUIRED  # Use 99 to fake a minimum-only constraint
              COMPONENTS WebAssembly X86
              OPTIONAL_COMPONENTS AArch64 ARM Hexagon NVPTX PowerPC RISCV)
 

src/CodeGen_LLVM.cpp

@@ -748,7 +748,7 @@ Value *CodeGen_LLVM::register_destructor(llvm::Function *destructor_fn, Value *o
     IRBuilderBase::InsertPoint here = builder->saveIP();
     BasicBlock *dtors = get_destructor_block();
 
-    builder->SetInsertPoint(dtors->getFirstNonPHI());
+    builder->SetInsertPoint(dtors->getFirstNonPHIIt());
 
     PHINode *error_code = dyn_cast<PHINode>(dtors->begin());
     internal_assert(error_code) << "The destructor block is supposed to start with a phi node\n";