Add cross compile patch llvm 20

Author: mcbarton

.github/workflows/emscripten.yml

@@ -306,7 +306,7 @@ jobs:
         else
           # Apply patches
           llvm_vers=$(echo "${{ matrix.clang-runtime }}" | tr '[:lower:]' '[:upper:]')
-          if [[ "${llvm_vers}" == "19" ]]; then
+          if [[ "${llvm_vers}" == "19" ]]||[[ "${llvm_vers}" == "20" ]]; then
             git apply -v ../patches/llvm/emscripten-clang${{ matrix.clang-runtime }}-*.patch
             echo "Apply emscripten-clang${{ matrix.clang-runtime }}-*.patch patches:"
           fi

patches/llvm/emscripten-clang20-1-CrossCompile.patch

@@ -0,0 +1,15 @@
+diff --git a/clang/lib/Interpreter/Wasm.cpp b/clang/lib/Interpreter/Wasm.cpp
+index aa10b160ccf8..184867e2b55f 100644
+--- a/clang/lib/Interpreter/Wasm.cpp
++++ b/clang/lib/Interpreter/Wasm.cpp
+@@ -76,8 +76,8 @@ llvm::Error WasmIncrementalExecutor::addModule(PartialTranslationUnit &PTU) {
+   llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
+       PTU.TheModule->getTargetTriple(), "", "", TO, llvm::Reloc::Model::PIC_);
+   PTU.TheModule->setDataLayout(TargetMachine->createDataLayout());
+-  std::string ObjectFileName = PTU.TheModule->getName().str() + ".o";
+-  std::string BinaryFileName = PTU.TheModule->getName().str() + ".wasm";
++  std::string ObjectFileName = "/tmp/" + PTU.TheModule->getName().str() + ".o";
++  std::string BinaryFileName = "/tmp/" + PTU.TheModule->getName().str() + ".wasm";
+ 
+   std::error_code Error;
+   llvm::raw_fd_ostream ObjectFileOutput(llvm::StringRef(ObjectFileName), Error);