[lldb] Fix an incorrect trigger of a per-module scratch context

which indirectly caused several ModuleSP shared pointers to live
longer than two tests expected them to.

The problem is that swift::performImportResolution() now apparently
also reports syntax errors in function bodies, so I had to add a
(terrible) heuristic to filter out actual module import errors.

rdar://135575668

Author: adrian-prantl

lldb/source/Plugins/ExpressionParser/Swift/SwiftExpressionParser.cpp

@@ -1389,9 +1389,13 @@ SwiftExpressionParser::ParseAndImport(
   // GetImplicitImports.
   swift::performImportResolution(*source_file);
 
-  if (expr_diagnostics.HasErrors())
-    return make_error<ModuleImportError>(
-        llvm::toString(expr_diagnostics.GetAllErrors()));
+  if (expr_diagnostics.HasErrors()) {
+    // FIXME: This could be done more elegantly.
+    std::string msg = llvm::toString(expr_diagnostics.GetAllErrors());
+    if (StringRef(msg).contains(": could not build module "))
+      return make_error<ModuleImportError>(msg);
+    return llvm::createStringError(msg);
+  }
 
   std::unique_ptr<SwiftASTManipulator> code_manipulator;
   if (repl || !playground) {

lldb/test/API/lang/swift/clangimporter/expr_import/TestSwiftExprImport.py

@@ -3,7 +3,6 @@
 from lldbsuite.test.decorators import *
 import lldbsuite.test.lldbutil as lldbutil
 
-@skipIf(bugnumber = "rdar://135575668")
 class TestSwiftExprImport(TestBase):
     # Don't run ClangImporter tests if Clangimporter is disabled.
     @skipIf(setting=('symbols.use-swift-clangimporter', 'false'))

lldb/test/API/lang/swift/expression/simple/TestSwiftSimpleExpressions.py

@@ -21,7 +21,6 @@
 
 
 class TestSwiftSimpleExpressions(TestBase):
-    @skipIf(bugnumber = "rdar://135575668")
     @swiftTest
     def test_simple_swift_expressions(self):
         """Tests that we can run simple Swift expressions correctly"""