Function LLVMDIBuilderCreateQualifiedType 

pub(crate) unsafe extern "C" fn LLVMDIBuilderCreateQualifiedType<'ll>(
    Builder: &DIBuilder<'ll>,
    Tag: c_uint,
    Type: &'ll Metadata,
) -> &'ll Metadata

Creates a “qualified type” in the C/C++ sense, by adding modifiers like const or volatile.