Compiler/RM48L952: Cannot find specific version of ARM Optimizing C/C++ Compiler User's Guide

Part Number:RM48L952

Tool/software: TI C/C++ Compiler

Hello,

I'm looking for v15.12.1LTS ARM Optimizing C/C++ Compiler User's Guide.

http://downloads.ti.com/docs/esd/SPNU151L/index.html

The link above says it's document version "L" but when I press the link, it redirects me to v17 version "O" 

http://processors.wiki.ti.com/index.php/TI_Compiler_Information

This link above links to the latest versions. 

http://processors.wiki.ti.com/index.php/Production_Compiler_Releases

This link above says that compiler v15 is still maintained, but I cannot find any documents relating to v15, or v16 for that matter as well.

From my understanding, LTS should be long term support and all relevant documents relating to LTS should be available, is that correct? I'd like a copy of the v15.12.LTS ARM Optimizing C/C++ Compiler User's Guide, if possible.

Thanks