Poison only class members in dtor, simpler test cases.

[nmusgrave]

Summary

Poison only class members in destructor, as opposed to poisoning inherited
members as well. Verify class members poisoned only once, before invoking
base class destructors.
Simplified test cases to focus on one feature at time.
Resolves issues from rL244819 (rolled back in revert rL244820).
Closed in rL244933

[eugenis]

test/CodeGenCXX/sanitize-dtor-fn-attribute.cpp

16 ↗

(On Diff #32020)

In the spirit of simplifying test cases, let's make this one purely about the attribute.

1. Remove the no-attribute case, it is tested somewhere else already.
2. No need to verify that No_SanD2Ev calls ~Vector. Check that: a. Destructors of No_San do not call sanitizer callback b. All destructors of Vector call sanitizer callback

[nmusgrave]

• test examines member dtor

[nmusgrave]

• removed comment

[nmusgrave]

• test marked as failing, since impl for nontrivial members pending

[eugenis]

test/CodeGenCXX/sanitize-dtor-fn-attribute.cpp

27 ↗

(On Diff #32022)

Now this does not check the sanitizer callback.
No need to check that D1 calls D2 - it;s not the point of this test case.
Just CHECK-NOT the sanitizer callback here and below.

[nmusgrave]

• test: non-trivial member modified to ensure sanitizing callback will be emitted

[eugenis]

LGTM

[nmusgrave]

Simplify test comment

test/CodeGenCXX/sanitize-dtor-callback.cpp

 // Test -fsanitize-memory-use-after-dtor
 // RUN: %clang_cc1 -fsanitize=memory -fsanitize-memory-use-after-dtor -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
 
-// Sanitizing dtor is emitted in dtor for every class
+// Sanitizing dtor is emitted in dtor for every class, and only
+// poisons once.
 
 struct Simple {
   int x;
   ~Simple() {}
 };
 Simple s;
 // Simple internal member is poisoned by compiler-generated dtor
 // CHECK-LABEL: define {{.*}}SimpleD1Ev