Temporarily disable rb_str_concat, add CI tests (https://github.com/Shopify/ruby/pull/407)

Make sure we can load the test-all runner and run test_yjit.rb

.cirrus.yml

@@ -163,6 +163,13 @@ yjit_task:
     bootstraptest/test_yjit_rust_port.rb \
     bootstraptest/test_yjit.rb
 
-  # FIXME: not currently working on CI, missing cargo
   # Check that we can do a full ruby build
-  #full_build_script: make -j
+  full_build_script: source $HOME/.cargo/env && make -j
+
+  # Check that we can build rdoc successfully
+  make_rdoc_script: source $HOME/.cargo/env && make -j rdoc
+
+  # Run John's YJIT instruction tests, and make sure we can load the test-all runner
+  test_yjit_script: source $HOME/.cargo/env && make test-all TESTS='test/ruby/test_yjit.rb' RUN_OPTS="--yjit-call-threshold=1"
+
+  # TODO: check that we can we run all of test-all successfully

yjit/src/codegen.rs

@@ -6134,7 +6134,7 @@ impl CodegenGlobals {
             //self.yjit_reg_method(rb_cString, "to_s", jit_rb_str_to_s);
             //self.yjit_reg_method(rb_cString, "to_str", jit_rb_str_to_s);
             self.yjit_reg_method(rb_cString, "bytesize", jit_rb_str_bytesize);
-            self.yjit_reg_method(rb_cString, "<<", jit_rb_str_concat);
+            //self.yjit_reg_method(rb_cString, "<<", jit_rb_str_concat);
             //self.yjit_reg_method(rb_cString, "+@", jit_rb_str_uplus);
 
             // Thread.current