Changed some recently added //+ usages to #+ and also fixed some //+ usages in some code generators.

tests/core/sys/windows/win32gen/win32gen.cpp

@@ -902,7 +902,7 @@ static void verify_error_helpers(ofstream& out) {
 }
 
 static void test_core_sys_windows(ofstream& out) {
-	out << "//+build windows" << endl
+	out << "#+build windows" << endl
 		<< "package " << __func__
 		<< " // generated by " << path(__FILE__).filename().replace_extension("").string() << endl
 		<< endl

tests/documentation/documentation_tester.odin

@@ -264,7 +264,7 @@ write_test_suite :: proc(example_tests: []Example_Test) {
 	test_runner := strings.builder_make()
 
 	strings.write_string(&test_runner,
-`//+private
+`#+private
 package documentation_verification
 
 import "core:os"