Add a minimal C interpreter example.
 - Demonstrates how to build a standalone tool which loads source code using the
   Driver and Frontend libraries, and then uses CodeGen and the JIT to actually
   execute the code.

 - Still more complicated than it should be, but hey its only 153 lines. :)

--
ddunbar@ozzy:tmp$ cat hello.c
#include <stdio.h>
int main() { printf("hello world\n"); return 0; }
ddunbar@ozzy:tmp$ clang-interpreter hello.c
hello world
--

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97133 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/examples/clang-interpreter/README.txt b/examples/clang-interpreter/README.txt
new file mode 100644
index 0000000..7dd45fa
--- /dev/null
+++ b/examples/clang-interpreter/README.txt
@@ -0,0 +1,17 @@
+This is an example of Clang based interpreter, for executing standalone C
+programs.
+
+It demonstrates the following features:
+ 1. Parsing standard compiler command line arguments using the Driver library.
+
+ 2. Constructing a Clang compiler instance, using the appropriate arguments
+    derived in step #1.
+
+ 3. Invoking the Clang compiler to lex, parse, syntax check, and then generate
+    LLVM code.
+
+ 4. Use the LLVM JIT functionality to execute the final module.
+
+The implementation has many limitations and is not designed to be a full fledged
+C interpreter. It is designed to demonstrate a simple but functional use of the
+Clang compiler libraries.