Address sphinx warnings

LanguageExtensions.rst:2191: WARNING: Title underline too short.
llvm-symbolizer.rst:157: Error in "code-block" directive: maximum 1 argument(s) allowed, 30 supplied.

clang/docs/LanguageExtensions.rst

@@ -2188,7 +2188,7 @@ argument.
   __builtin_preserve_access_index(v->j);
 
 ``__builtin_unique_stable_name``
-------------------------
+--------------------------------
 
 ``__builtin_unique_stable_name()`` is a builtin that takes a type or expression and
 produces a string literal containing a unique name for the type (or type of the

llvm/docs/CommandGuide/llvm-symbolizer.rst

@@ -155,10 +155,11 @@ shows the default absolute path, the second --basenames, and the third
 shows --relativenames.
 
 .. code-block:: console
+
   $ pwd
   /tmp
   $ clang -g foo/test.cpp -o test.elf
-  $ llvm-symbolizer --obj=test.elf 0x4004a0 
+  $ llvm-symbolizer --obj=test.elf 0x4004a0
   main
   /tmp/foo/test.cpp:15:0
   $ llvm-symbolizer --obj=test.elf 0x4004a0 --basenames
@@ -167,7 +168,7 @@ shows --relativenames.
   $ llvm-symbolizer --obj=test.elf 0x4004a0 --relativenames
   main
   foo/test.cpp:15:0
-   
+
 OPTIONS
 -------