Prebuild aws-lc

[sfod]

This PR is the same as awslabs/aws-crt-cpp#648

Issue #, if available:

At configuration time, s2n-tls performs a number of feature probes against libcrypto in order to configure itself. In the current implementation of aws-crt-python build system, the correct libcrypto does not yet exist (nor are aws-lc's headers visible to the feature check, for that matter). This results in a misconfigured s2n-tls.

Unfortunately, there is no easy way to change s2n-tls to be configured at build time, because CMake standard functionality for this (try_compile function) can be used only at configuration time.

Description of changes:

Build and install aws-lc into a build directory at configuration time, so libcrypto can be used by s2n-tls.

This PR depends on awslabs/aws-c-common#1144 and awslabs/aws-c-cal#197

I checked this PR by using the following build command:

python3 -m pip install --no-binary :all: --verbose .

Prior to this PR, s2n-tls feature probes looked like this

-- S2N found target: crypto
-- CMAKE_AR found: /usr/bin/ar
-- CMAKE_RANLIB found: /usr/bin/ranlib
-- CMAKE_OBJCOPY found: /usr/bin/objcopy
-- feature S2N_ATOMIC_SUPPORTED: FALSE
-- feature S2N_CLOEXEC_SUPPORTED: FALSE
-- feature S2N_CLOEXEC_XOPEN_SUPPORTED: FALSE
-- feature S2N_CLONE_SUPPORTED: FALSE
-- feature S2N_CPUID_AVAILABLE: FALSE
-- feature S2N_DIAGNOSTICS_POP_SUPPORTED: FALSE
-- feature S2N_DIAGNOSTICS_PUSH_SUPPORTED: FALSE
-- feature S2N_EXECINFO_AVAILABLE: FALSE
-- feature S2N_FALL_THROUGH_SUPPORTED: FALSE
-- feature S2N_FEATURES_AVAILABLE: FALSE
-- feature S2N_KTLS_SUPPORTED: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_EC_KEY_CHECK_FIPS: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_AEAD_TLS: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_MD5_SHA1_HASH: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_MD_CTX_SET_PKEY_CTX: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_RC4: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_FLAG_NO_CHECK_TIME: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_HKDF: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_KYBER: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_RSA_PSS_SIGNING: FALSE
-- feature S2N_LIBCRYPTO_SUPPORTS_X509_STORE_LIST: FALSE
-- feature S2N_LINUX_SENDFILE: FALSE
-- feature S2N_MADVISE_SUPPORTED: FALSE
-- feature S2N_MINHERIT_SUPPORTED: FALSE
-- feature S2N_STACKTRACE: FALSE

Now s2n feature probes look like this

-- FOUND AWS-LC CRYPTO cmake config - static
-- Using libcrypto from the cmake path
-- CMAKE_AR found: /usr/bin/ar
-- CMAKE_RANLIB found: /usr/bin/ranlib
-- CMAKE_OBJCOPY found: /usr/bin/objcopy
-- feature S2N_ATOMIC_SUPPORTED: TRUE
-- feature S2N_CLOEXEC_SUPPORTED: TRUE
-- feature S2N_CLOEXEC_XOPEN_SUPPORTED: TRUE
-- feature S2N_CLONE_SUPPORTED: TRUE
-- feature S2N_CPUID_AVAILABLE: TRUE
-- feature S2N_DIAGNOSTICS_POP_SUPPORTED: TRUE
-- feature S2N_DIAGNOSTICS_PUSH_SUPPORTED: TRUE
-- feature S2N_EXECINFO_AVAILABLE: TRUE
-- feature S2N_FALL_THROUGH_SUPPORTED: TRUE
-- feature S2N_FEATURES_AVAILABLE: TRUE
-- feature S2N_KTLS_SUPPORTED: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_EC_KEY_CHECK_FIPS: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_AEAD_TLS: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_MD5_SHA1_HASH: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_MD_CTX_SET_PKEY_CTX: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_EVP_RC4: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_FLAG_NO_CHECK_TIME: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_HKDF: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_KYBER: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_RSA_PSS_SIGNING: TRUE
-- feature S2N_LIBCRYPTO_SUPPORTS_X509_STORE_LIST: TRUE
-- feature S2N_LINUX_SENDFILE: TRUE
-- feature S2N_MADVISE_SUPPORTED: TRUE
-- feature S2N_MINHERIT_SUPPORTED: FALSE
-- feature S2N_STACKTRACE: TRUE

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