Implement initial support for function attributes, including parser, printer,
resolver support.

Still TODO are verifier support (to make sure you don't use an attribute for a
function in another module) and the TODO in ModuleParser::finalizeModule that I
will handle in the next patch.

PiperOrigin-RevId: 209361648
diff --git a/lib/IR/Builders.cpp b/lib/IR/Builders.cpp
index be334ef..5fce94c 100644
--- a/lib/IR/Builders.cpp
+++ b/lib/IR/Builders.cpp
@@ -111,6 +111,10 @@
   return TypeAttr::get(type, context);
 }
 
+FunctionAttr *Builder::getFunctionAttr(Function *value) {
+  return FunctionAttr::get(value, context);
+}
+
 //===----------------------------------------------------------------------===//
 // Affine Expressions, Affine Maps, and Integet Sets.
 //===----------------------------------------------------------------------===//