Add missing forward declaration [NFC]

llvm-svn: 231326

diff --git a/polly/include/polly/CodeGen/IslAst.h b/polly/include/polly/CodeGen/IslAst.h
index 9d09dd7..530e0b6 100644 (file)
--- a/polly/include/polly/CodeGen/IslAst.h
+++ b/polly/include/polly/CodeGen/IslAst.h
@@ -31,6 +31,7 @@ namespace llvm {
 class raw_ostream;
 }
 
+struct isl_pw_aff;
 struct isl_ast_node;
 struct isl_ast_expr;
 struct isl_ast_build;