Revert "[docs] Add support for Markdown documentation in Sphinx"

The buildbots have an old version of Sphinx (need at least 1.3).  Revert until they are upgraded.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337513 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Bigcheese

docs/MarkdownQuickstartTemplate.md

@@ -31,9 +31,7 @@
 templates_path = ['_templates']
 
 # The suffix of source filenames.
-source_suffix = ['.rst', '.md']
-
-source_parsers = {'.md': 'recommonmark.parser.CommonMarkParser'}
+source_suffix = '.rst'
 
 # The encoding of source files.
 #source_encoding = 'utf-8-sig'

docs/conf.py

@@ -79,7 +79,6 @@ representation.
    yaml2obj
    HowToSubmitABug
    SphinxQuickstartTemplate
-   MarkdownQuickstartTemplate
    Phabricator
    TestingGuide
    tutorial/index
@@ -293,7 +292,6 @@ For API clients and LLVM developers.
    XRayFDRFormat
    PDB/index
    CFIVerify
-   SpeculativeLoadHardening
 
 :doc:`WritingAnLLVMPass`
    Information on how to write LLVM transformations and analyses.
@@ -427,9 +425,6 @@ For API clients and LLVM developers.
 :doc:`CFIVerify`
   A description of the verification tool for Control Flow Integrity.
 
-:doc:`SpeculativeLoadHardening`
-  A description of the Speculative Load Hardening mitigation for Spectre v1.
-
 Development Process Documentation
 =================================