lib.systems: Add examples & helpers for MSVC

lib/systems/default.nix

@@ -120,6 +120,8 @@ let
         libc =
           if final.isDarwin then
             "libSystem"
+          else if final.isMsvc then
+            "ucrt"
           else if final.isMinGW then
             "msvcrt"
           else if final.isWasi then

lib/systems/examples.nix

@@ -372,6 +372,17 @@ rec {
     useLLVM = true;
   };
 
+  # Target the MSVC ABI
+  x86_64-windows = {
+    config = "x86_64-pc-windows-msvc";
+    useLLVM = true;
+  };
+
+  aarch64-windows = {
+    config = "aarch64-pc-windows-msvc";
+    useLLVM = true;
+  };
+
   # BSDs
 
   aarch64-freebsd = {

lib/systems/inspect.nix

@@ -344,6 +344,10 @@ rec {
       kernel = kernels.windows;
       abi = abis.gnu;
     };
+    isMsvc = {
+      kernel = kernels.windows;
+      abi = abis.msvc;
+    };
     isWasi = {
       kernel = kernels.wasi;
     };