Fix bug 10797: Crash: "cast<Ty>() argument of incompatible type!" assert when analyzing ICU.

Patch by Jean-Daniel Dupas. Thanks for spotting and fixing!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138757 91177308-0d34-0410-b5e6-96231b3b80d8

lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp

@@ -201,9 +201,11 @@ static SymbolRef getSymbolForRegion(CheckerContext &C,
   if (!isa<SymbolicRegion>(R)) {
     // Implicit casts (ex: void* -> char*) can turn Symbolic region into element
     // region, if that is the case, get the underlining region.
-    if (const ElementRegion *ER = dyn_cast<ElementRegion>(R))
+    if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
       R = ER->getAsArrayOffset().getRegion();
-    else
+      if (!isa<SymbolicRegion>(R))
+        return 0;
+    } else
       return 0;
   }
   return cast<SymbolicRegion>(R)->getSymbol();

test/Analysis/keychainAPI.m

@@ -304,3 +304,9 @@ void DellocWithCFStringCreate4(CFAllocatorRef alloc) {
     CFRelease(userStr);
   }
 }
+
+//Example from bug 10797.
+__inline__ static
+const char *__WBASLLevelString(int level) {
+  return "foo";
+}