[build-script] Cross-compile sourcekit-lsp for arm64

Currently, when building an open source toolchain, SourceKit-LSP is only built for x86_64. Copy the cross-compilation config from swiftpm.py to also produce a fat sourcekit-lsp executable for both x86_64 and arm64.

rdar://78039145

Author: ahoppen

utils/swift_build_support/swift_build_support/products/indexstoredb.py

@@ -105,18 +105,24 @@ def run_build_script_helper(action, host_target, product, args,
     elif args.enable_tsan:
         helper_cmd.extend(['--sanitize', 'thread'])
 
-    if not product.is_darwin_host(
-            host_target) and product.is_cross_compile_target(host_target):
-        helper_cmd.extend(['--cross-compile-host', host_target])
-        build_toolchain_path = install_destdir + args.install_prefix
-        resource_dir = '%s/lib/swift' % build_toolchain_path
-        helper_cmd += [
-            '--cross-compile-config',
-            targets.StdlibDeploymentTarget.get_target_for_name(host_target).platform
-            .swiftpm_config(args, output_dir=build_toolchain_path,
-                            swift_toolchain=toolchain_path,
-                            resource_path=resource_dir)
-        ]
+    # Pass Cross compile host info
+    if product.has_cross_compile_hosts(args):
+        if product.is_darwin_host(host_target):
+            helper_cmd += ['--cross-compile-hosts']
+            for cross_compile_host in args.cross_compile_hosts:
+                helper_cmd += [cross_compile_host]
+        elif product.is_cross_compile_target(host_target):
+            helper_cmd += ['--cross-compile-hosts', host_target,
+                           '--skip-cmake-bootstrap']
+            build_toolchain_path = product.host_install_destdir(
+                host_target) + args.install_prefix
+            resource_dir = '%s/lib/swift' % build_toolchain_path
+            helper_cmd += [
+                '--cross-compile-config',
+                targets.StdlibDeploymentTarget.get_target_for_name(host_target).platform
+                .swiftpm_config(args, output_dir=build_toolchain_path,
+                                swift_toolchain=toolchain_path,
+                                resource_path=resource_dir)]
 
     if action == 'install' and product.product_name() == "sourcekitlsp":
         helper_cmd.extend([