16k: soong: Add the C flag -D__BIONIC_NO_PAGE_SIZE_MACRO flag to x86-64

To simulate 16k page size in x86-64 cuttefish, it is necessary
to compile the shared libraries and binaries with max-page-size greater
than 4096.

Bug: 309816695
Test: source build/envsetup.sh
      lunch aosp_cf_x86_64_phone_pgagnostic-trunk-userdebug
      m
Change-Id: I32670ef2c25fdcefec11bd07ba41cd0ea96c92bd

cc/config/x86_64_device.go

@@ -104,7 +104,15 @@ func init() {
 	})
 
 	// Clang cflags
-	exportedVars.ExportStringListStaticVariable("X86_64Cflags", x86_64Cflags)
+	exportedVars.ExportStringList("X86_64Cflags", x86_64Cflags)
+	pctx.VariableFunc("X86_64Cflags", func(ctx android.PackageVarContext) string {
+		flags := x86_64Cflags
+		if ctx.Config().PageSizeAgnostic() {
+			flags = append(flags, "-D__BIONIC_NO_PAGE_SIZE_MACRO")
+		}
+		return strings.Join(flags, " ")
+	})
+
 	exportedVars.ExportStringListStaticVariable("X86_64Cppflags", x86_64Cppflags)
 
 	// Yasm flags