Silence some Sphinx diagnostics in an attempt to get the documentation builder back to green (http://lab.llvm.org:8011/builders/llvm-sphinx-docs/builds/1895).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292271 91177308-0d34-0410-b5e6-96231b3b80d8

docs/Extensions.rst

@@ -61,7 +61,7 @@ types ``IMAGE_REL_I386_SECREL`` (32-bit) or ``IMAGE_REL_AMD64_SECREL`` (64-bit).
 the target.  It corresponds to the COFF relocation types
 ``IMAGE_REL_I386_SECTION`` (32-bit) or ``IMAGE_REL_AMD64_SECTION`` (64-bit).
 
-.. code-block:: gas
+.. code-block:: none
 
   .section .debug$S,"rn"
     .long 4

docs/LangRef.rst

@@ -3997,7 +3997,7 @@ DIFile
 
 ``DIFile`` nodes represent files. The ``filename:`` can include slashes.
 
-.. code-block:: llvm
+.. code-block:: none
 
     !0 = !DIFile(filename: "path/to/file", directory: "/path/to/dir",
                  checksumkind: CSK_MD5,

docs/NVPTXUsage.rst

@@ -356,6 +356,7 @@ The value of this flag is determined by the "nvvm-reflect-ftz" module flag.
 The following sets the ftz flag to 1.
 
 .. code-block:: llvm
+
     !llvm.module.flag = !{!0}
     !0 = !{i32 4, !"nvvm-reflect-ftz", i32 1}