Fix docs/Coroutines.rst syntax highlighting on Linux

Summary:
s/code-block:: C++/code-block:: c++ in docs/Coroutines.rst .

Patch by Gor Nishanov!  Edited by Sanjoy to fix a missing s/C/c/.

Reviewers: sanjoy, rengolin

Differential Revision: https://reviews.llvm.org/D22832

llvm-svn: 276806
diff --git a/llvm/docs/Coroutines.rst b/llvm/docs/Coroutines.rst
index 2c4d720..9d89a7e 100644
--- a/llvm/docs/Coroutines.rst
+++ b/llvm/docs/Coroutines.rst
@@ -73,7 +73,7 @@
 Let's look at an example of an LLVM coroutine with the behavior sketched
 by the following pseudo-code.
 
-.. code-block:: C++
+.. code-block:: c++
 
   void *f(int n) {
      for(;;) {
@@ -274,7 +274,7 @@
 
 Let's consider the coroutine that has more than one suspend point:
 
-.. code-block:: C++
+.. code-block:: c++
 
   void *f(int n) {
      for(;;) {
@@ -528,7 +528,7 @@
 Python frontend would inject two more suspend points, so that the actual code
 looks like this:
 
-.. code-block:: C
+.. code-block:: c
 
   void* coroutine(int n) {
     int current_value; 
@@ -542,7 +542,7 @@
 
 and python iterator `__next__` would look like:
 
-.. code-block:: C++
+.. code-block:: c++
 
   int __next__(void* hdl) {
     coro.resume(hdl);
@@ -1109,7 +1109,7 @@
 Consider the following example. A coroutine takes two parameters `a` and `b`
 that has a destructor and a move constructor.
 
-.. code-block:: C++
+.. code-block:: c++
 
   struct A { ~A(); A(A&&); bool foo(); void bar(); };