SI-6439 Avoid spurious REPL warnings about companionship

`val m` isn't a companion of `trait m`, check the pair of
eponymous symbols are a ((class|trait), object) pair before
emitting the warning.

In order to correctly check this one a type alias is involved,
`definedSymbols` must avoid normalizing through type aliases.
AFAICT this is an improvement to the other clients of that Map,
one such power mode progression is demonstrated at the end
of the test case.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/interpreter/IMain.scala b/src/compiler/scala/tools/nsc/interpreter/IMain.scala
index b46d28dec3..a55f0af116 100644
--- a/src/compiler/scala/tools/nsc/interpreter/IMain.scala
+++ b/src/compiler/scala/tools/nsc/interpreter/IMain.scala
@@ -386,6 +386,7 @@ class IMain(initialSettings: Settings, protected val out: JPrintWriter) extends
       oldReq <- definedNameMap get name.companionName
       newSym <- req.definedSymbols get name
       oldSym <- oldReq.definedSymbols get name.companionName
+      if Seq(oldSym, newSym).permutations exists { case Seq(s1, s2) => s1.isClass && s2.isModule }
     } {
       afterTyper(replwarn(s"warning: previously defined $oldSym is not a companion to $newSym."))
       replwarn("Companions must be defined together; you may wish to use :paste mode for this.")
@@ -970,7 +971,7 @@ class IMain(initialSettings: Settings, protected val out: JPrintWriter) extends
     // }
     lazy val definedSymbols = (
       termNames.map(x => x -> applyToResultMember(x, x => x)) ++
-      typeNames.map(x => x -> compilerTypeOf(x).typeSymbol)
+      typeNames.map(x => x -> compilerTypeOf(x).typeSymbolDirect)
     ).toMap[Name, Symbol] withDefaultValue NoSymbol
 
     lazy val typesOfDefinedTerms = mapFrom[Name, Name, Type](termNames)(x => applyToResultMember(x, _.tpe))