LibC: Link statically with libstdc++

This allows us to have the implementation of __cxa_demangle in libc.so.

Libraries/LibC/CMakeLists.txt

@@ -66,7 +66,7 @@ add_custom_command(
 )
 
 set(SOURCES ${LIBC_SOURCES} ${AK_SOURCES} ${ELF_SOURCES})
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -nostdlib")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -static-libstdc++")
 serenity_libc(LibC c)
 target_link_libraries(LibC crt0)
 add_dependencies(LibC LibM)

Libraries/LibELF/DynamicObject.cpp

@@ -420,11 +420,6 @@ Elf32_Addr DynamicObject::patch_plt_entry(u32 relocation_offset)
     ASSERT(relocation.type() == R_386_JMP_SLOT);
 
     auto sym = relocation.symbol();
-    if (StringView { sym.name() } == "__cxa_demangle") {
-        dbgln("__cxa_demangle is currently not supported for shared objects");
-        // FIXME: Where is it defined?
-        ASSERT_NOT_REACHED();
-    }
 
     u8* relocation_address = relocation.address().as_ptr();
     auto res = lookup_symbol(sym);

Libraries/LibELF/Loader.cpp

@@ -264,10 +264,7 @@ String Loader::symbolicate(u32 address, u32* out_offset) const
 #else
             auto& demangled_name = symbol.demangled_name;
             if (demangled_name.is_null()) {
-
-                // FIXME: Temporarily disabled demangling since it is currently not supported with shared libraries
-                demangled_name = symbol.name;
-                // demangled_name = demangle(symbol.name);
+                demangled_name = demangle(symbol.name);
             }
 #endif