MFC	r256448, r257029;

Make di_blocks unsigned in UFS1 as is the case already for UFS2.
 Most of the code between UFS1 and UFS2 is shared so this change
 is pretty safe. Not only this makes UFS1 and 2 consistent but it
 also matches what NetBSD and MacOS X have for some years now.

UFS2: make di_extsize unsigned.
 di_extsize is the EA size and as such it should be unsigned.
 Adjust related types for consistency.

Reviewed by:	mckusick
MFC r241959:

Fix a number of other clang warnings in libstdc++, which could appear
when building other C++ software with it.  Also fix one actual bug in
libsupc++, which was exposed by such a warning.  This latter fix is the
only functional change.

This is required for newer versions of gcc and clang which have
stricter warnings about parenthesis in C++ programs.
MFC r258712;

libcpp: fix an underflow.

Similar fix seen in Apple's gcc42.

Obtained from:	OpenBSD (Rev 1.2)
MFC after:	2 weeks
MFC r244673:

Fix the __glibcxx_min and __glibcxx_max macros for a signed wchar_t.

This seems to be needed by newer compilers.
MFC r257987:
  Initialize prot variable.

  PR:		177417