Change test-all suite to enable testing each test in separate ractors.

This tests for ractor safety issues as well as concurrency issues.

You can enable these tests with RUBY_TESTS_WITH_RACTORS=X when running
`make test-all TESTS=test/ruby`. These ractor tests are currently only
working for tests under the "test/ruby" directory, so don't run any
others with this ENV var set or you will get errors. You should also use
the `.exludes-ractor` excludes directory.

For example:

```
EXCLUDES=test/.excludes-ractor RUBY_TESTS_WITH_RACTORS=3 TESTS=test/ruby make test-all
```

This will create 3 ractors for each test method, run the test method
inside each ractor and then call `join` on the ractors. Then, it's ready
to process the next test method. The reason we do this instead of taking
all the tests and dividing them between the number of ractors is:

* We want to run each test under concurrency load to test whether
  or not it is safe under ractors. If it isn't safe, we know it's
  something to do with this specific test.

* If we get a segfault or error, we know the error is coming from this
  test alone, not interactions with other tests.

Author: luke-gruber

ext/-test-/file/fs.c

@@ -105,6 +105,9 @@ get_noatime_p(VALUE self, VALUE str)
 void
 Init_fs(VALUE module)
 {
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    rb_ext_ractor_safe(true);
+#endif
     VALUE fs = rb_define_module_under(module, "Fs");
     rb_define_module_function(fs, "fsname", get_fsname, 1);
     rb_define_module_function(fs, "noatime?", get_noatime_p, 1);

ext/-test-/integer/init.c

@@ -5,6 +5,9 @@
 void
 Init_integer(void)
 {
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    rb_ext_ractor_safe(true);
+#endif
     VALUE mBug = rb_define_module("Bug");
     VALUE klass = rb_define_class_under(mBug, "Integer", rb_cObject);
     TEST_INIT_FUNCS(init);

ext/-test-/iter/break.c

@@ -19,6 +19,10 @@ iter_break_value(VALUE self, VALUE val)
 void
 Init_break(VALUE klass)
 {
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    // Mark this extension as Ractor-safe.
+    rb_ext_ractor_safe(true);
+#endif
     VALUE breakable = rb_define_module_under(klass, "Breakable");
     rb_define_module_function(breakable, "iter_break", iter_break, 0);
     rb_define_module_function(breakable, "iter_break_value", iter_break_value, 1);

ext/-test-/iter/init.c

@@ -5,6 +5,11 @@
 void
 Init_iter(void)
 {
+
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    // Mark this extension as Ractor-safe.
+    rb_ext_ractor_safe(true);
+#endif
     VALUE mBug = rb_define_module("Bug");
     VALUE klass = rb_define_module_under(mBug, "Iter");
     TEST_INIT_FUNCS(init);

ext/-test-/iter/yield.c

@@ -10,6 +10,11 @@ yield_block(int argc, VALUE *argv, VALUE self)
 void
 Init_yield(VALUE klass)
 {
+
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    // Mark this extension as Ractor-safe.
+    rb_ext_ractor_safe(true);
+#endif
     VALUE yield = rb_define_module_under(klass, "Yield");
 
     rb_define_method(yield, "yield_block", yield_block, -1);

ext/-test-/rb_call_super_kw/rb_call_super_kw.c

@@ -9,6 +9,10 @@ rb_call_super_kw_m(int argc, VALUE *argv, VALUE self)
 void
 Init_rb_call_super_kw(void)
 {
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    // Mark this extension as Ractor-safe.
+    rb_ext_ractor_safe(true);
+#endif
     VALUE module = rb_define_module("Bug");
     module = rb_define_module_under(module, "RbCallSuperKw");
     rb_define_method(module, "m", rb_call_super_kw_m, -1);

ext/-test-/stack/stack.c

@@ -30,6 +30,9 @@ asan_p(VALUE klass)
 void
 Init_stack(VALUE klass)
 {
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    RB_EXT_RACTOR_SAFE(true);
+#endif
     rb_define_singleton_method(rb_cThread, "alloca_overflow", stack_alloca_overflow, 0);
     rb_define_singleton_method(rb_cThread, "asan?", asan_p, 0);
 }

test/.excludes-ractor/Prism/TestCompilePrism.rb

@@ -0,0 +1,27 @@
+# Prism::TestCompilePrism#test_repeated_proc_params../ruby/st.c:2621: Assertion Failed: set_rebuild_table_with:new_tab->num_entries == tab->num_entries
+exclude(/^test_/, "FIXME: bug. Skip all tests for now")
+
+exclude(/^test_GlobalVariable/, "global variables")
+exclude(:test_ClassVariableTargetNode, "class variables")
+exclude(:test_ClassVariableAndWriteNode, "class variables")
+exclude(:test_ClassVariableOperatorWriteNode, "class variables")
+exclude(:test_ClassVariableOrWriteNode, "class variables")
+exclude(:test_ClassVariableWriteNode, "class variables")
+exclude(:test_ConstantWriteNode, "global side  effects")
+exclude(:test_InstanceVariableTargetNode, "class ivars")
+exclude(:test_InstanceVariableReadNode, "class ivars")
+exclude(:test_InstanceVariableWriteNode, "class ivars")
+exclude(:test_EmbeddedVariableNode, "class ivars")
+exclude(:test_InterpolatedMatchLastLineNode, "global variables")
+exclude(:test_InterpolatedRegularExpressionNode, "global variables")
+exclude(:test_InterpolatedStringNode, "global variables")
+exclude(:test_InterpolatedSymbolNode, "global variables")
+exclude(:test_AliasGlobalVariableNode, "global variables")
+exclude(:test_ClassVariableReadNode, "class variables")
+exclude(:test_ForNode_gvar, "gvars")
+exclude(:test_PostExecutionNode_set_ivar, "set ivar of main")
+exclude(:test_PinnedVariableNode_ractor_unsafe, "ractor incompatible")
+exclude(:test_DefinedNode_ractor_unsafe, "ractor incompatible")
+exclude(:test_ConstantPathOrWriteNode_ractor_unsafe, "ractor incompatible")
+exclude(:test_ConstantPathOperatorWriteNode_ractor_unsafe, "ractor incompatible")
+exclude(:test_IfNode_ractor_unsafe, "gvars")

test/.excludes-ractor/RubyVM.rb

@@ -0,0 +1,2 @@
+exclude(:test_of_proc_and_method, "ractor incompatible")
+exclude(:test_parse_file_raises_syntax_error, "ractor incompatible")

test/.excludes-ractor/TestAlias.rb

@@ -0,0 +1,2 @@
+exclude(:test_alias_class_method_added, "class ivars")
+exclude(:test_alias_module_method_added, "module ivars")