ksym() alias/replacement to sym()

Lesson 9: Replace "stack" to "kstack".

Fix warning issue for Lesson 9: the stack is deprecated and will be removed in the future. Use kstack instead

kstack alias/replacement to stack 

fix tracepoint wildcards

cmake: add BUILD_TESTING support

Probe list optimizations and improvements

use structs with semicolons

- Moved regex init code outside search_probe function (avoiding to be
called again at every invocation)
- inlined search_probe function
- Added std::regex::optimize flag to regex
- Fixed search of "software*" and "hardware*"

Before:

time ./bpftrace -l '*xfs*'|wc -l
2363

real	0m1.841s
user	0m1.576s
sys	0m0.261s

After:

time ./bpftrace -l '*xfs*'|wc -l
2363

real	0m1.179s
user	0m0.904s
sys	0m0.271s

struct definitions that end with semicolons

If we use clang to build bpftrace instead of GCC, it will complain about
trying to use the `-std-c++14` flag to comile headers.c. If we force
cmake to skip this flag on `.c` files, clang is not able to link
libresources.a correctly.

This patch changes the resources workflow to generate a .cpp file
instead, and to have a `src/headers.h` with all headers we currently
use. With this approach we get a safer linkage because the same
definition for the header strings is being used in clang_parser.cpp and
in headers.cpp.

Fixes: https://github.com/iovisor/bpftrace/issues/350

bpftrace -l tweaks for consistency

Fix wrong package name in build instructions

This corresponds to the change in the install instructions for Ubuntu
outlined in #335.

Make bpftrace -l list sofware and hardware types (#44)

tracepoint shortcut t breaks args

hist: split negative, zero, and one into separate buckets

Add --version

- Also refactored code in attached_probe.cpp and
ast/semantic_analyzer.cpp to use the sw/hw lists instead of the
hardcoded probe names.

Currently tests/ requires pulling gtest from git, which is far from
ideal for distribution builds (not to mention we don't need to unit test
in an RPM build). So add the ability to disable tests/ builds.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

lhist: interval notation tweak

runqlat.bt: remove if semicolon