Install OpenSSL-compat libcrypto.pc and libssl.pc with the shim

[justsmth]

Description of changes:

OpenSSL installs three pkg-config files: openssl.pc, libcrypto.pc, and libssl.pc; the OpenSSL shim currently installs only openssl.pc. Since pkg-config resolves packages by filename, third-party packages whose .pc files declare Requires.private: libcrypto (libssh2, among others) fail to resolve against a shim install -- sometimes silently, e.g. the Rust crate libssh2-sys falls back to its vendored libssh2 instead of using the shim.

This installs compat libcrypto.pc and libssl.pc whenever the shim is enabled and the libraries carry the -awslc suffix. The compat files are generated with OpenSSL-identical content rather than symlinked to the suffixed pc files: the suffixed files' Cflags: -I.../include/aws-lc leaks transitively into every consumer of libcrypto, and that extra path can displace other packages' include dirs in toolchains that treat pkg-config include paths as single-valued (cargo links-metadata is last-wins, which breaks libgit2-sys via libssh2-sys). The compat files instead point includedir at the plain include/ directory, where the shim already installs its include/openssl symlink. Libs: still references the suffixed libraries.

Call-outs:

• openssl.pc under the shim now has Requires: libssl libcrypto instead of the suffixed names, matching genuine OpenSSL and picking up the compat include dir.
• Default Linux shared builds (no ENABLE_DIST_PKG) also enable the shim with suffixed libraries, so they gain the compat pc files too -- consistent with those builds already installing the libcrypto.so/libssl.so symlinks and openssl.pc.
• When libraries are unsuffixed (macOS, Windows, default static), the primary pc files already have the OpenSSL filenames and output is byte-identical to before.
• New in this revision: BUILD_LIBSSL=OFF builds no longer install libssl.pc (previously a dangling one was installed) and drop libssl from the Requires: line of aws-lc.pc/openssl.pc.

Testing:

Extended tests/ci/run_dist_pkg_install_tests.sh: with the shim enabled, asserts the compat files exist, all three OpenSSL names resolve without leaking the cohabitant include dir, the compile-and-run smoke test passes against the libcrypto name, and a synthetic consumer pc file with Requires.private: libcrypto resolves (the libssh2 pattern, without needing libssh2). With the shim disabled, asserts none of the three names are installed.

Also extended tests/ci/run_install_shared_and_static.sh to assert the pc files installed by default (non-dist-pkg) Linux builds, covering the shared config that newly gains the compat files.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.

[github-actions]

🔒 Security Review — View Report

Please review before merging.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.19%. Comparing base (8cca33b) to head (3c5eed8).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3370      +/-   ##
==========================================
- Coverage   78.44%   78.19%   -0.25%     
==========================================
  Files         695      695              
  Lines      124223   124220       -3     
  Branches    17267    17263       -4     
==========================================
- Hits        97451    97139     -312     
- Misses      25850    26158     +308     
- Partials      922      923       +1     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.