[flang] Fix bug checking SAVE attribute

[tskeith]

Summary

We were treating a SAVE statement without an entity-list as if it applied to all
items in a scoping unit, but it only applies to the allowed ones (8.6.14(1)).

[jeanPerier]

Why not updating semantics::IsSaved to test IsFunctionResult instead like it is doing with IsDummy ?
Lowering relies on IsSaved to indicate whether something is implicitly or explicitly saved, so with this patch it looks like we would still create a global for f2b even if we should not.

[PeteSteinfeld]

All builds, tests, and looks good.

[tskeith]

Move fix into IsSaved.

[tskeith]

In D82309#2107006, @jeanPerier wrote:

Why not updating semantics::IsSaved to test IsFunctionResult instead like it is doing with IsDummy ?
Lowering relies on IsSaved to indicate whether something is implicitly or explicitly saved, so with this patch it looks like we would still create a global for f2b even if we should not.

OK, I've done that.

[jeanPerier]

LGTM, thanks

flang/lib/Evaluate/tools.cpp

if (scopeKind == Scope::Kind::Module) {
                object && object->init()) {
       return true;
     } else if (IsProcedurePointer(symbol) &&
         symbol.get<ProcEntityDetails>().init()) {
       return true;
     } else if (const Symbol * block{FindCommonBlockContaining(symbol)};
                block && block->attrs().test(Attr::SAVE)) {
       return true;
-    } else if (IsDummy(symbol)) {
+    } else if (IsDummy(symbol) || IsFunctionResult(symbol)) {
       return false;
     } else {
       for (; !scope->IsGlobal(); scope = &scope->parent()) {
         if (scope->hasSAVE()) {
           return true;
         }
       }
     }

flang/test/Semantics/resolve45.f90

 end
 
 function f2(x, y)
   !ERROR: SAVE attribute may not be applied to function result 'f2'
   real, save :: f2
   !ERROR: SAVE attribute may not be applied to dummy argument 'x'
   complex, save :: x
   allocatable :: y
+  integer :: y
   !ERROR: SAVE attribute may not be applied to dummy argument 'y'
-  integer, save :: y
+  save :: y
+end
+
+! SAVE statement should not trigger the above errors
+function f2b(x, y)
+  real :: x, y
+  save
 end
 
 subroutine s3(x)
   !ERROR: SAVE attribute may not be applied to dummy argument 'x'
   procedure(integer), pointer, save :: x
   !ERROR: Procedure 'y' with SAVE attribute must also have POINTER attribute
   procedure(integer), save :: y
 end