Added 32 bit and 64 bit links for Python 2.7.12

Solved issue https://github.com/MicrosoftDocs/visualstudio-docs/issues/1697#issue-370816572

Added Debug Symbol links for 32 bit and 64 bit Python 2.7.12

Author: minkushjain

docs/python/debugging-symbols-for-mixed-mode-c-cpp-python.md

@@ -72,6 +72,7 @@ If you downloaded symbols separately, follow the steps below to make Visual Stud
 | 3.3.2 | [32-bit](https://www.org/ftp/python/3.3.2/python-3.3.2-pdb.zip) - [64-bit](https://www.org/ftp/python/3.3.2/python-3.3.2.amd64-pdb.zip) |
 | 3.3.1 | [32-bit](https://www.org/ftp/python/3.3.1/python-3.3.1-pdb.zip) - [64-bit](https://www.org/ftp/python/3.3.1/python-3.3.1.amd64-pdb.zip) |
 | 3.3.0 | [32-bit](https://www.org/ftp/python/3.3.0/python-3.3.0-pdb.zip) - [64-bit](https://www.org/ftp/python/3.3.0/python-3.3.0.amd64-pdb.zip) |
+| 2.7.12 | [32-bit](https://www.python.org/ftp/python/2.7.12/python-2.7.12-pdb.zip) - [64-bit](https://www.python.org/ftp/python/2.7.12/python-2.7.12.amd64-pdb.zip) |
 | 2.7.11 | [32-bit](https://www.python.org/ftp/python/2.7.11/python-2.7.11-pdb.zip) - [64-bit](https://www.python.org/ftp/python/2.7.11/python-2.7.11.amd64-pdb.zip) |
 | 2.7.10 | [32-bit](https://www.python.org/ftp/python/2.7.10/python-2.7.10-pdb.zip) - [64-bit](https://www.python.org/ftp/python/2.7.10/python-2.7.10.amd64-pdb.zip) |
 | 2.7.9 | [32-bit](https://www.python.org/ftp/python/2.7.9/python-2.7.9-pdb.zip) - [64-bit](https://www.python.org/ftp/python/2.7.9/python-2.7.9.amd64-pdb.zip) |