Change std::{lower,upper}_bound to llvm::{lower,upper}_bound or llvm::partition_point. NFC

llvm-svn: 365006
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index db8e74e..cf02215 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -228,12 +228,11 @@
 
     if (Found) {
       Comment = MaybeBeforeDecl + 1;
-      assert(Comment == std::lower_bound(RawComments.begin(), RawComments.end(),
-                                         &CommentAtDeclLoc, Compare));
+      assert(Comment ==
+             llvm::lower_bound(RawComments, &CommentAtDeclLoc, Compare));
     } else {
       // Slow path.
-      Comment = std::lower_bound(RawComments.begin(), RawComments.end(),
-                                 &CommentAtDeclLoc, Compare);
+      Comment = llvm::lower_bound(RawComments, &CommentAtDeclLoc, Compare);
     }
   }