fix(various): decrease size of distributed artifacts [backport 1.17] (#6521)

Backport fd5f7b2 from #6517 to 1.17.

* link libdatadog shared library using -flto
* run `unlink -g` on every .so packaged after setup

This combination of operations shaves about half of the total size of
`ddtrace`. This does not strip the symbol table, nor does it suppress
generation of `.eh_frame`. Thus, debugging the released artifacts should
still be possible.

As far as I know, none of our infrastructure makes use of debuginfo.
Accordingly, I can't think of any reason, nor means, to test whether
this impacts anything.

## Checklist

- [X] Change(s) are motivated and described in the PR description.
- [X] Testing strategy is described if automated tests are not included
in the PR.
- [X] Risk is outlined (performance impact, potential for breakage,
maintainability, etc).
- [X] Change is maintainable (easy to change, telemetry, documentation).
- [X] [Library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
are followed. If no release note is required, add label
`changelog/no-changelog`.
- [X] Documentation is included (in-code, generated user docs, [public
corp docs](https://github.com/DataDog/documentation/)).
- [X] Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist

- [x] Title is accurate.
- [x] No unnecessary changes are introduced.
- [x] Description motivates each change.
- [x] Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes unless absolutely necessary.
- [x] Testing strategy adequately addresses listed risk(s).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] Release note makes sense to a user of the library.
- [x] Reviewer has explicitly acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment.
- [x] Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

Co-authored-by: David Sanchez <[email protected]>
Co-authored-by: Gabriele N. Tornetta <[email protected]>

Author: 3 people

setup.py

@@ -3,6 +3,7 @@
 import platform
 import re
 import shutil
+import subprocess
 import sys
 import tarfile
 
@@ -291,6 +292,10 @@ def run(self):
 
 
 class CMakeBuild(build_ext):
+    @staticmethod
+    def strip_symbols(so_file):
+        subprocess.check_output(["strip", "-g", so_file])
+
     def build_extension(self, ext):
         tmp_iast_file_path = os.path.abspath(self.get_ext_fullpath(ext.name))
         tmp_iast_path = os.path.join(os.path.dirname(tmp_iast_file_path))
@@ -358,6 +363,12 @@ def build_extension(self, ext):
             shutil.copy(os.path.join(IAST_DIR, tmp_filename), tmp_iast_file_path)
         else:
             build_ext.build_extension(self, ext)
+            if CURRENT_OS == "Linux":
+                for ext in self.extensions:
+                    try:
+                        self.strip_symbols(self.get_ext_fullpath(ext.name))
+                    except Exception:
+                        pass
 
 
 long_description = """
@@ -471,7 +482,7 @@ def get_ddup_ext():
                         ],
                         include_dirs=LibDatadogDownload.get_include_dirs(),
                         extra_objects=LibDatadogDownload.get_extra_objects(),
-                        extra_compile_args=["-std=c++17"],
+                        extra_compile_args=["-std=c++17", "-flto"],
                         language="c++",
                     )
                 ],