Add test for loading module .pm files (#466)

* add tests for =defn implementation

* add new file and new tests for loading .pm modules

S10-packages/basic.t

@@ -6,7 +6,7 @@ use lib $?FILE.IO.parent(2).add("packages");
 use Test;
 use Test::Util;
 
-plan 83;
+plan 85;
 
 my regex fairly_conclusive_platform_error {:i ^\N* <<Null?>>}
 
@@ -200,6 +200,13 @@ eval-lives-ok q' module MapTester { (1, 2, 3).map: { $_ } } ',
     is EVAL('use PM6; pm6_works()'), 42, 'can call subs exported from .pm6 module';
 }
 
+# the following was added during the roast name change from "*.pm" to
+# "*.pm6" to ensure the ".pm" suffix is still valid for old code
+{
+    eval-lives-ok 'use PM', 'can load a module ending in .pm';
+    is EVAL('use PM; pm_works()'), 42, 'can call subs exported from .pm module';
+}
+
 # package Foo; is perl 5 code;
 # RT #75458
 {

packages/PM.pm

@@ -0,0 +1,9 @@
+#============ DO NOT RENAME THIS FILE SUFFIX TO "PM.pm6" =============
+#
+# THIS FILE EXISTS TO TEST PROPER LOADING OF MODULES WITH A ".pm" FILE
+# EXTENSION.
+#
+#=====================================================================
+module PM {
+    sub pm_works() is export { 42 }
+}