Fix up compiler and standard library build when there's no host Swift

Author: DougGregor

lib/AST/ASTScope.cpp

@@ -148,6 +148,7 @@ void ASTScope::unqualifiedLookup(
   if (auto *s = SF->getASTContext().Stats)
     ++s->getFrontendCounters().NumASTScopeLookups;
 
+#if SWIFT_BUILD_SWIFT_SYNTAX
   // Perform validation of SwiftLexicalLookup if option
   // Feature::UnqualifiedLookupValidation is enabled and lookup was not
   // performed in a macro.
@@ -171,6 +172,9 @@ void ASTScope::unqualifiedLookup(
   } else {
     ASTScopeImpl::unqualifiedLookup(SF, loc, consumer);
   }
+#else
+    ASTScopeImpl::unqualifiedLookup(SF, loc, consumer);
+#endif
 }
 
 llvm::SmallVector<LabeledStmt *, 4> ASTScope::lookupLabeledStmts(

stdlib/public/core/SwiftifyImport.swift

@@ -58,6 +58,8 @@ public enum _SwiftifyInfo {
 ///
 /// Parameter paramInfo: information about how the function uses the pointer passed to it. The
 /// safety of the generated wrapper function depends on this info being extensive and accurate.
+#if hasFeature(Macros)
 @attached(peer, names: overloaded)
 public macro _SwiftifyImport(_ paramInfo: _SwiftifyInfo..., typeMappings: [String: String] = [:]) =
     #externalMacro(module: "SwiftMacros", type: "SwiftifyImportMacro")
+#endif