$NetBSD: patch-lib_Basic_Targets_OSTargets.h,v 1.10 2024/07/07 14:00:21 wiz Exp $

Add __illumos__ if the bootstrap compiler also defines it.
Sync SunOS default defines with what GCC uses.

--- lib/Basic/Targets/OSTargets.h.orig	2023-11-28 08:52:28.000000000 +0000
+++ lib/Basic/Targets/OSTargets.h
@@ -639,25 +639,21 @@ protected:
   void getOSDefines(const LangOptions &Opts, const llvm::Triple &Triple,
                     MacroBuilder &Builder) const override {
     DefineStd(Builder, "sun", Opts);
+#if defined(__illumos__)
+    DefineStd(Builder, "__illumos__", Opts);
+#endif
     DefineStd(Builder, "unix", Opts);
     Builder.defineMacro("__svr4__");
     Builder.defineMacro("__SVR4");
-    // Solaris headers require _XOPEN_SOURCE to be set to 600 for C99 and
-    // newer, but to 500 for everything else.  feature_test.h has a check to
-    // ensure that you are not using C99 with an old version of X/Open or C89
-    // with a new version.
-    if (Opts.C99)
-      Builder.defineMacro("_XOPEN_SOURCE", "600");
-    else
-      Builder.defineMacro("_XOPEN_SOURCE", "500");
+    // Compatibility with GCC to satisfy <sys/feature_tests.h> requirements.
     if (Opts.CPlusPlus) {
-      Builder.defineMacro("__C99FEATURES__");
+      Builder.defineMacro("__STDC_VERSION__", "199901L");
+      Builder.defineMacro("_XOPEN_SOURCE", "600");
       Builder.defineMacro("_FILE_OFFSET_BITS", "64");
+      Builder.defineMacro("_LARGEFILE_SOURCE");
+      Builder.defineMacro("_LARGEFILE64_SOURCE");
+      Builder.defineMacro("__EXTENSIONS__");
     }
-    // GCC restricts the next two to C++.
-    Builder.defineMacro("_LARGEFILE_SOURCE");
-    Builder.defineMacro("_LARGEFILE64_SOURCE");
-    Builder.defineMacro("__EXTENSIONS__");
     if (Opts.POSIXThreads)
       Builder.defineMacro("_REENTRANT");
     if (this->HasFloat128)