LibDebug: Allow DWARF compilation unit header version <= 4

I think this is okay, the main thing to protect against is new versions
of the format that we don't know about yet.

This happens because an .S file compiled into libc.so has version 2
instead of version 4 like everything else.

Fixes #4491.

Libraries/LibDebug/Dwarf/DwarfInfo.cpp

@@ -60,7 +60,7 @@ void DwarfInfo::populate_compilation_units()
 
         stream >> Bytes { &compilation_unit_header, sizeof(compilation_unit_header) };
         ASSERT(compilation_unit_header.address_size == sizeof(u32));
-        ASSERT(compilation_unit_header.version == 4);
+        ASSERT(compilation_unit_header.version <= 4);
 
         u32 length_after_header = compilation_unit_header.length - (sizeof(CompilationUnitHeader) - offsetof(CompilationUnitHeader, version));
         m_compilation_units.empend(*this, unit_offset, compilation_unit_header);