Move CRuby-specific prism files to top level

compile.c

@@ -13372,4 +13372,4 @@ rb_iseq_ibf_load_extra_data(VALUE str)
     return extra_str;
 }
 
-#include "prism/prism_compiler.c"
+#include "prism_compile.c"

test/ruby/test_compile_prism.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module Prism
-  class ISeqTest < Test::Unit::TestCase
+  class TestCompilePrism < Test::Unit::TestCase
     def test_empty_program
       test_prism_eval("")
     end
@@ -334,10 +334,11 @@ module Prism
     end
 
     def test_prism_eval(source)
-      compare_eval(source)
+      $VERBOSE, verbose_bak = nil, $VERBOSE
 
       begin
-        $VERBOSE, verbose_bak = nil, $VERBOSE
+        compare_eval(source)
+
         # Test "popped" functionality
         compare_eval("#{source}; 1")
       ensure

tool/sync_default_gems.rb

@@ -398,12 +398,6 @@ module SyncDefaultGems
       cp_r("#{upstream}/spec", "spec/syntax_suggest")
       cp_r("#{upstream}/exe/syntax_suggest", "libexec/syntax_suggest")
     when "prism"
-      # We don't want to remove prism-specific files that existing in ruby/ruby
-      # that do not exist in ruby/prism, so we temporarily move them out of the
-      # prism dir, wipe the prism dir, and then put them back.
-      mv("prism/prism_init.c", ".")
-      mv("prism/prism_compiler.c", ".")
-      mv("test/prism/iseq_test.rb", ".")
       rm_rf(%w[test/prism prism])
 
       cp_r("#{upstream}/ext/prism", "prism")
@@ -420,9 +414,6 @@ module SyncDefaultGems
       rm_rf("prism/templates/java")
 
       rm("prism/extconf.rb")
-      mv("prism_init.c", "prism/")
-      mv("prism_compiler.c", "prism/")
-      mv("iseq_test.rb", "test/prism/")
     else
       sync_lib gem, upstream
     end