Bug 1475882 - clang-analyzer: Enable clang-analyzer-cplusplus.NewDeleteLeaks check. r=andi

Check for memory leaks. Traces memory managed by new/ delete. There are currently no clang-analyzer-cplusplus.NewDeleteLeaks warnings in mozilla-central!

https://clang-analyzer.llvm.org/available_checks.html

MozReview-Commit-ID: 3tmwR26UB8K

--HG--
extra : rebase_source : 3796cc6b61c03e83ce8b390e3342b870085b2ed2
extra : source : 3389fb54d2e3daee38db38503b37e9d994878bcd

tools/clang-tidy/config.yaml

@@ -13,6 +13,8 @@ clang_checkers:
     publish: !!bool no
   - name: clang-analyzer-cplusplus.NewDelete
     publish: !!bool yes
+  - name: clang-analyzer-cplusplus.NewDeleteLeaks
+    publish: !!bool yes
   - name: clang-analyzer-deadcode.DeadStores
     publish: !!bool yes
   - name: clang-analyzer-security.FloatLoopCounter

tools/clang-tidy/test/clang-analyzer-cplusplus.NewDeleteLeaks.cpp

@@ -0,0 +1,6 @@
+// https://clang-analyzer.llvm.org/available_checks.html
+
+void test()
+{
+  int *p = new int;
+} // warning

tools/clang-tidy/test/clang-analyzer-cplusplus.NewDeleteLeaks.json

@@ -0,0 +1 @@
+"[[\"warning\", \"Potential leak of memory pointed to by 'p'\", \"clang-analyzer-cplusplus.NewDeleteLeaks\"]]"