public static ResourceFile getLanguageExternalFile(Language lang, String name)
			throws IOException {
		String filename = getLanguageExternalNameValue(lang, name);
		return filename != null ? new ResourceFile(getLanguageDefinitionDirectory(lang), filename)
				: null;
	}
Returns a file that has been referenced in the specified {@link Language language's}
ldefs description via a
<pre>&lt;external_name tool="<b>name</b>" name="<b>value</b>"/&gt;</pre>
entry.
 
@param lang {@link Language} to query
@param name name of the option in the ldefs file
@return file pointed to by the specified external_name tool entry 
@throws IOException if not a sleigh lang
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFUtil.java