Add tests for the parsing of hist trigger expressions; and to validate expression evaluation. Link: https://lkml.kernel.org/r/20211029183339.3216491-5-kaleshsingh@google.com Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> (cherry picked from commit 4e9f63c9e5c2597692567ee1cb0851a21104a531) Bug: 146055070 Bug: 145972256 Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Change-Id: I4c5f12675ab6ec2641a45ab1852e07b8adcd827a