[flang] Fixed a crash

[PeteSteinfeld]

Summary

I found a small test case that caused a crash when derived type
definitions have parameters without definitions.

[PeteSteinfeld]

flang/test/Semantics/resolve33.f90

33–38

This test case is not sufficient to trigger the crash. I need to add the declaration of a variable of the type to do that.

[PeteSteinfeld]

1. Updating D79282: [flang] Fixed a crash #
2. Enter a brief description of the changes included in this update.
3. The first line is used as subject, next lines as comment. #
4. If you intended to create a new revision, use:
5. $ arc diff --create

Added a declaration to make the test case crash the compiler

The declaration of the type wasn't enough to cause the crash. I needed to
declare an object of that type.

flang/lib/Semantics/type.cpp

if (maybeKeyword) {
         // Resolve the keyword's symbol
         maybeKeyword->v.symbol = const_cast<Symbol *>(&it->get());
         attr = it->get().get<TypeParamDetails>().attr();
       }
     } else if (nextNameIter != parameterNames.end()) {
       name = *nextNameIter++;
       auto it{std::find_if(parameterDecls.begin(), parameterDecls.end(),
           [&](const Symbol &symbol) { return symbol.name() == name; })};
-      CHECK(it != parameterDecls.end());
+      if (it == parameterDecls.end()) {
+        break;
+      }
       attr = it->get().get<TypeParamDetails>().attr();
     } else {
       messages.Say(name_,
           "Too many type parameters given for derived type '%s'"_err_en_US,
           typeSymbol_.name());
       break;
     }
     if (FindParameter(name)) {

flang/test/Semantics/resolve33.f90

type t4(a)
     integer(8), len :: d
   end type
   type t5(a, b)
     integer, len :: a
     integer, len :: b
     !ERROR: Type parameter, component, or procedure binding 'a' already defined in this type
     integer, len :: a
   end type
+  !ERROR: No definition found for type parameter 'k'
+  !ERROR: No definition found for type parameter 'l'
+  type :: t6(k, l)
+    !ERROR: Must be a constant value
+    character(kind=k, len=l) :: d3
+  end type
+  type(t6(2, 10)) :: x3
 end module