Fix even more Clang warnings.

This patch disables shift-sign-overflow warnings for now. It also
fixes most -Wfloat-equal warnings and -Wextra-semi warnings.

llvm-svn: 343438
diff --git a/libcxx/include/memory b/libcxx/include/memory
index df629b9..6e292a5 100644
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -2131,7 +2131,9 @@
   _LIBCPP_INLINE_VISIBILITY
   constexpr explicit
   __compressed_pair_elem(_Up&& __u)
-      : __value_(_VSTD::forward<_Up>(__u)){};
+      : __value_(_VSTD::forward<_Up>(__u))
+    {
+    }
 
   template <class... _Args, size_t... _Indexes>
   _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
@@ -2168,7 +2170,8 @@
   _LIBCPP_INLINE_VISIBILITY
   constexpr explicit
   __compressed_pair_elem(_Up&& __u)
-      : __value_type(_VSTD::forward<_Up>(__u)){};
+      : __value_type(_VSTD::forward<_Up>(__u))
+  {}
 
   template <class... _Args, size_t... _Indexes>
   _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14