Add disable_omit_fp support for LLVM (#2045)

Fixes mono/mono#18417

src/mono/mono/mini/mini-llvm-cpp.cpp

@@ -454,6 +454,14 @@ mono_llvm_add_func_attr (LLVMValueRef func, AttrKind kind)
 	unwrap<Function> (func)->addAttribute (AttributeList::FunctionIndex, convert_attr (kind));
 }
 
+void
+mono_llvm_add_func_attr_nv (LLVMValueRef func, const char *attr_name, const char *attr_value)
+{
+	AttrBuilder NewAttrs;
+	NewAttrs.addAttribute (attr_name, attr_value);
+	unwrap<Function> (func)->addAttributes (AttributeList::FunctionIndex, NewAttrs);
+}
+
 void
 mono_llvm_add_param_attr (LLVMValueRef param, AttrKind kind)
 {

src/mono/mono/mini/mini-llvm-cpp.h

@@ -140,6 +140,9 @@ mono_llvm_set_alignment_ret (LLVMValueRef val, int alignment);
 void
 mono_llvm_add_func_attr (LLVMValueRef func, AttrKind kind);
 
+void
+mono_llvm_add_func_attr_nv (LLVMValueRef func, const char *attr_name, const char *attr_value);
+
 void
 mono_llvm_add_param_attr (LLVMValueRef param, AttrKind kind);
 

src/mono/mono/mini/mini-llvm.c

@@ -8559,6 +8559,9 @@ emit_method_inner (EmitContext *ctx)
 
 	mono_llvm_add_func_attr (method, LLVM_ATTR_UW_TABLE);
 
+	if (cfg->disable_omit_fp)
+		mono_llvm_add_func_attr_nv (method, "no-frame-pointer-elim", "true");
+
 	if (cfg->compile_aot) {
 		if (is_externally_callable (ctx, cfg->method)) {
 			LLVMSetLinkage (method, LLVMExternalLinkage);