SI-8907 Don't force symbol info in isModuleNotMethod

Test case by Jason.

RefChecks adds the lateMETHOD flag lazily in its info transformer.
This means that forcing the `sym.info` may change the value of
`sym.isMethod`.

0ccdb151f introduced a check to force the info in isModuleNotMethod,
but it turns out this leads to errors on stub symbols (SI-8907).

The responsibility to force info is transferred to callers, which
is the case for other operations on symbols, too.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/Flatten.scala b/src/compiler/scala/tools/nsc/transform/Flatten.scala
index fa53ef48b5..4662ef6224 100644
--- a/src/compiler/scala/tools/nsc/transform/Flatten.scala
+++ b/src/compiler/scala/tools/nsc/transform/Flatten.scala
@@ -77,8 +77,11 @@ abstract class Flatten extends InfoTransform {
               if (sym.isTerm && !sym.isStaticModule) {
                 decls1 enter sym
                 if (sym.isModule) {
-                  // Nested, non-static moduls are transformed to methods.
-                  assert(sym.isMethod, s"Non-static $sym should have the lateMETHOD flag from RefChecks")
+                  // In theory, we could assert(sym.isMethod), because nested, non-static moduls are
+                  // transformed to methods (lateMETHOD flag added in RefChecks). But this requires
+                  // forcing sym.info (see comment on isModuleNotMethod), which forces stub symbols
+                  // too eagerly (SI-8907).
+
                   // Note that module classes are not entered into the 'decls' of the ClassInfoType
                   // of the outer class, only the module symbols are. So the current loop does
                   // not visit module classes. Therefore we set the LIFTED flag here for module