[Macros] Eliminate overaggressive cycle breaking in getSemanticAttrs()

This cycle break means that some attributes introduced by
member-attribute macros aren't getting processed. I'm still reducing a
test case while I look for a fix, but for now I'm reverting this
change to address a regression for macros.

Fixes rdar://108456284.

Author: DougGregor

lib/AST/Decl.cpp

@@ -372,12 +372,10 @@ OrigDeclAttributes Decl::getOriginalAttrs() const {
 }
 
 DeclAttributes Decl::getSemanticAttrs() const {
-  if (!getASTContext().evaluator.hasActiveResolveMacroRequest()) {
-    auto mutableThis = const_cast<Decl *>(this);
-    (void)evaluateOrDefault(getASTContext().evaluator,
-                            ExpandMemberAttributeMacros{mutableThis},
-                            { });
-  }
+  auto mutableThis = const_cast<Decl *>(this);
+  (void)evaluateOrDefault(getASTContext().evaluator,
+                          ExpandMemberAttributeMacros{mutableThis},
+                          { });
 
   return getAttrs();
 }

test/Macros/macro_expand_peers.swift

@@ -149,8 +149,9 @@ struct S2 {
   }
 
   #if TEST_DIAGNOSTICS
-  // expected-error@+1{{cannot find 'nonexistent' in scope}}
-  @addCompletionHandlerArbitrarily(nonexistent)
+  // FIXME: Causes reference cycles
+  // should have error {{cannot find 'nonexistent' in scope}}
+  // @addCompletionHandlerArbitrarily(nonexistent)
   func h(a: Int, for b: String, _ value: Double) async -> String {
     return b
   }