Subzero: Added ASan quarantine for recently freed objects

tests_lit/asan_tests/doublefree.ll

Index: tests_lit/asan_tests/doublefree.ll
diff --git a/tests_lit/asan_tests/doublefree.ll b/tests_lit/asan_tests/doublefree.ll
new file mode 100644
index 0000000000000000000000000000000000000000..ca79ec41567d3111f72e9589ae61c37653881989
--- /dev/null
+++ b/tests_lit/asan_tests/doublefree.ll
@@ -0,0 +1,24 @@
+; Test that double frees are detected
+
+; REQUIRES: no_minimal_build
+
+; RUN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUN:     --fsanitize-address --sz=-allow-externally-defined-symbols \
+; RUN:     %t.pexe -o %t && %t 2>&1 | FileCheck --check-prefix=ERR %s
+; RUN: llvm-as %s -o - | pnacl-freeze > %t.pexe && %S/../../pydir/szbuild.py \
+; RUN:     --fsanitize-address --sz=-allow-externally-defined-symbols -O2 \
+; RUN:     %t.pexe -o %t && %t 2>&1 | FileCheck --check-prefix=ERR %s
+
+declare external i32 @malloc(i32)
+declare external void @free(i32)
+declare external void @exit(i32)
+
+define void @_start(i32 %arg) {
+  %alloc = call i32 @malloc(i32 42)
+  call void @free(i32 %alloc)
+  call void @free(i32 %alloc)
+  call void @exit(i32 1)
+  ret void
+}
+
+; ERR: Double free of object at