Fix build

Author: stevapple

Package.swift

@@ -77,3 +77,13 @@ let package = Package(
             dependencies: ["TSCUtility", "TSCTestSupport"]),
     ]
 )
+
+// FIXME: conditionalise these flags since SwiftPM 5.3 and earlier will crash
+// for platforms they don't know about.
+#if os(Windows)
+  if let TSCBasic = package.targets.first(where: { $0.name == "TSCBasic" }) {
+    TSCBasic.cxxSettings = [
+      .define("_CRT_SECURE_NO_WARNINGS", .when(platforms: [.windows])),
+    ]
+  }
+#endif

Sources/TSCBasic/CMakeLists.txt

@@ -57,9 +57,10 @@ target_compile_options(TSCBasic PUBLIC
   # Ignore secure function warnings on Windows.
   "$<$<PLATFORM_ID:Windows>:SHELL:-Xcc -D_CRT_SECURE_NO_WARNINGS>")
 target_link_libraries(TSCBasic PUBLIC
-  TSCLibc)
+  TSCLibc
+  SwiftSystem)
 target_link_libraries(TSCBasic PRIVATE
-   TSCclibc)
+  TSCclibc)
 if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
   if(Foundation_FOUND)
     target_link_libraries(TSCBasic PUBLIC