[flang] Fix check for coarray actual passed to implicit interface

The check for a coarray actual argument being passed to a procedure
with an implicit interface was incorrect, yielding false positives
for coindexed objects and scalar coarrays.  Fix, and correct a test.

Author: klausler

flang/lib/Semantics/check-call.cpp

@@ -67,10 +67,6 @@ static void CheckImplicitInterfaceArg(evaluate::ActualArgument &arg,
           "Null pointer argument requires an explicit interface"_err_en_US);
     } else if (auto named{evaluate::ExtractNamedEntity(*expr)}) {
       const Symbol &symbol{named->GetLastSymbol()};
-      if (symbol.Corank() > 0) {
-        messages.Say(
-            "Coarray argument requires an explicit interface"_err_en_US);
-      }
       if (evaluate::IsAssumedRank(symbol)) {
         messages.Say(
             "Assumed rank argument requires an explicit interface"_err_en_US);

flang/test/Semantics/call13.f90

@@ -22,8 +22,8 @@ subroutine s(assumedRank, coarray, class, classStar, typeStar)
   call implicit10(1, 2, keyword=3)  ! 15.4.2.2(1)
   !ERROR: Assumed rank argument requires an explicit interface
   call implicit11(assumedRank)  ! 15.4.2.2(3)(c)
-  !ERROR: Coarray argument requires an explicit interface
-  call implicit12(coarray)  ! 15.4.2.2(3)(d)
+  call implicit12(coarray)  ! ok
+  call implicit12a(coarray[1]) ! ok
   !ERROR: Parameterized derived type actual argument requires an explicit interface
   call implicit13(pdtx)  ! 15.4.2.2(3)(e)
   call implicit14(class)  ! ok