kn: re-enable cross-compilation on Linux hosts (#145)

Author: lauzadis

build-support/src/main/kotlin/aws/sdk/kotlin/gradle/crt/CMakeTasks.kt

@@ -121,6 +121,12 @@ private fun Project.registerCmakeConfigureTask(
                 }
             }
 
+            // FIXME? Compiling s2n-tls on GitHub Actions Ubuntu image (without Docker / cross-compilation) has errors like:
+            // In function ‘s2n_hash_algorithms_init’
+            // error: implicit declaration of function ‘EVP_MD_free’;
+            // See https://github.com/aws/s2n-tls/blob/529b01a8363962a4e3809c9d9ee34fdd098fb0ba/tests/features/S2N_LIBCRYPTO_SUPPORTS_PROVIDERS.c#L29
+            // and https://github.com/aws/s2n-tls/blob/529b01a8363962a4e3809c9d9ee34fdd098fb0ba/crypto/s2n_hash.c#L85
+
             // executed from root build dir which is where CMakeLists.txt is
             // We _could_ use the undocumented -H flag but that will be harder to make work inside docker
             args.add(".")
@@ -207,8 +213,7 @@ private fun runCmake(project: Project, target: KotlinNativeTarget, cmakeArgs: Li
         workingDir(project.rootDir)
         val exeArgs = cmakeArgs.toMutableList()
         val exeName = when {
-            // Only cross-compile on non-Linux hosts
-            !HostManager.hostIsLinux && target.konanTarget in crossCompileTargets -> {
+            target.konanTarget in crossCompileTargets -> {
                 // cross compiling via dockcross - set the docker exe to cmake
                 val containerScriptArgs = listOf("--args", "--pull=missing", "--", "cmake")
                 exeArgs.addAll(0, containerScriptArgs)