Add new Asm/C++/Java/Make warning patterns

* Change some incorrectly-classified logtags warnings to C++.
* Fix gpylint warnings of long lines in html_writer.py.

Test: warn.py --url=http://cs/android --separator='?l=' build.log > warnings.html
Test: warn.py --gencsv build.log > warnings.csv
Change-Id: I98c01dadfd72b202d81ef7c94e93c42182f6065c

tools/warn/java_warn_patterns.py

@@ -74,6 +74,8 @@ warn_patterns = [
                 [r'.*\.class\): warning: Cannot find annotation method .+ in']),
     java_medium('No class/method in SDK ...',
                 [r'.*\.java:.*: warning: No such (class|method) .* for SDK']),
+    java_medium('Unknown enum constant',
+                [r'unknown_source_file: warning: unknown enum constant .+']),
     # Warnings generated by Error Prone
     java_medium('Non-ascii characters used, but ascii encoding specified',
                 [r".*: warning: unmappable character for encoding ascii"]),
@@ -207,6 +209,8 @@ warn_patterns = [
            'Logging or rethrowing exceptions should usually be preferred to catching and calling printStackTrace'),
     medium('CatchFail',
            'Ignoring exceptions and calling fail() is unnecessary, and makes test output less useful'),
+    medium('ChangedAbstract',
+           'Method has changed \'abstract\' qualifier'),
     medium('ClassCanBeStatic',
            'Inner class is non-static but does not reference enclosing class'),
     medium('ClassNewInstance',
@@ -355,6 +359,8 @@ warn_patterns = [
            'equals method doesn\'t override Object.equals'),
     medium('NotCloseable',
            'Not closeable'),
+    medium('NullableCollection',
+           'Method should not return a nullable collection'),
     medium('NullableConstructor',
            'Constructors should not be annotated with @Nullable since they cannot return null'),
     medium('NullableDereference',