Updates for bison 3.5

- %pure-parser is now implied for C++ templates
- must work around auto-generated code printing a std::string* which is
  an error in android-base/logging.h

Bug: 31194194
Test: build
Change-Id: Ia6538a3d03318925cc9d5deab59b1865c4a652c8
diff --git a/aidl.cpp b/aidl.cpp
index 4d11155..dba8624 100644
--- a/aidl.cpp
+++ b/aidl.cpp
@@ -357,7 +357,7 @@
   }
 
   string line;
-  unsigned lineno = 1;
+  int lineno = 1;
   for ( ; line_reader->ReadLine(&line); ++lineno) {
     if (line.empty() || line.compare(0, 2, "//") == 0) {
       // skip comments and empty lines