[analyzer] Don't even try to convert floats to booleans for now.

We now have symbols with floating-point type to make sure that
(double)x == (double)x comes out true, but we still can't do much with
these. For now, don't even bother trying to create a floating-point zero
value; just give up on conversion to bool.

PR14634, C++ edition.

llvm-svn: 190953
diff --git a/clang/test/Analysis/casts.cpp b/clang/test/Analysis/casts.cpp
new file mode 100644
index 0000000..3395391
--- /dev/null
+++ b/clang/test/Analysis/casts.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=core -analyzer-store=region -verify %s
+// expected-no-diagnostics
+
+bool PR14634(int x) {
+  double y = (double)x;
+  return !y;
+}
+
+bool PR14634_implicit(int x) {
+  double y = (double)x;
+  return y;
+}