[analyzer] Syntactic matcher for leaks associated with run loop and autoreleasepool
A checker for detecting leaks resulting from allocating temporary
autoreleasing objects before starting the main run loop.
Checks for two antipatterns:
1. ObjCMessageExpr followed by [[NARunLoop mainRunLoop] run] in the same
autorelease pool.
2. ObjCMessageExpr followed by [[NARunLoop mainRunLoop] run] in no
autorelease pool.
Happens-before relationship is modeled purely syntactically.
rdar://
39299145
Differential Revision: https://reviews.llvm.org/D49528
llvm-svn: 337876