Reduce/reduce conflicts are now reported as errors.

Test: make hidl-gen, hidl_test
Bug: 31617732
Change-Id: If1e06e7ab5d4f46418a3c9a0042d44debb876b0e
diff --git a/hidl-gen_y.yy b/hidl-gen_y.yy
index 5efe93c..30c5aaf 100644
--- a/hidl-gen_y.yy
+++ b/hidl-gen_y.yy
@@ -50,8 +50,11 @@
 %parse-param { android::AST *ast }
 %lex-param { void *scanner }
 %pure-parser
+%glr-parser
 %skeleton "glr.cc"
 
+%expect-rr 0
+
 %token<str> ENUM
 %token<str> EXTENDS
 %token<str> FQNAME