From: Andrew Udvare <audvare@gmail.com>
Subject: [PATCH] Tell the demangler that stdlib.h exists

alloca.c only includes stdlib.h when HAVE_STDLIB_H is defined, so without it
free() and abort() are implicitly declared, which GCC 14 rejects outright.
Upstream already defines it in the 2.x copy of the same demangler.

diff --git a/demanglegnu/CMakeLists.txt b/demanglegnu/CMakeLists.txt
index e1a90ab..bc81126 100644
--- a/demanglegnu/CMakeLists.txt
+++ b/demanglegnu/CMakeLists.txt
@@ -14,7 +14,7 @@ add_library(demanglegnu STATIC
 	xstrdup.c
 )
 include_directories(.)
-target_compile_definitions(demanglegnu PRIVATE -DHAVE_STRING_H=1)
+target_compile_definitions(demanglegnu PRIVATE -DHAVE_STRING_H=1 -DHAVE_STDLIB_H=1)
 if(APPLE)
 	target_compile_options(demanglegnu PRIVATE -Wno-implicit-function-declaration)
 endif()