Start migration of static analyzer to using the
implicit lvalue-to-rvalue casts that John McCall
recently introduced.  This causes a whole bunch
of logic in the analyzer for handling lvalues
to vanish.  It does, however, raise a few issues
in the analyzer w.r.t to modeling various constructs
(e.g., field accesses to compound literals).

The .c/.m analysis test cases that fail are
due to a missing lvalue-to-rvalue cast that
will get introduced into the AST.  The .cpp
failures were more than I could investigate in
one go, and the patch was already getting huge.
I have XFAILED some of these tests, and they
should obviously be further investigated.

Some highlights of this patch include:

- CFG no longer requires an lvalue bit for
  CFGElements
- StackFrameContext doesn't need an 'asLValue'
  flag
- The "VisitLValue" path from GRExprEngine has
  been eliminated.

Besides the test case failures (XFAILed), there
are surely other bugs that are fallout from
this change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@121960 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Checker/Environment.cpp b/lib/Checker/Environment.cpp
index f2893ea..7bf2929 100644
--- a/lib/Checker/Environment.cpp
+++ b/lib/Checker/Environment.cpp
@@ -62,8 +62,7 @@
         QualType CT = C->getType();
         if (CT->isVoidType())
           return UnknownVal();
-        if (C->getCastKind() == CK_NoOp ||
-            C->getCastKind() == CK_LValueToRValue) { // temporary workaround
+        if (C->getCastKind() == CK_NoOp) {
           E = C->getSubExpr();
           continue;
         }