* include/stdint.h (INT8_C): Also define for __cplusplus >= 201103L.
        If __INT8_C is defined, use GNU C preprocessor builtin-macro
        for the definition.
        (INT16_C INT32_C, INT64_C, UINT8_C, UINT16_C, UINT32_C): Likewise.
        (UINT64_C, INTMAX_C, UINTMAX_C): Likewise.
        * include/stdint.h [!__USING_MINT8] (UINT8_MAX): Provide (signed)
        int value.
        (SIZE_MAX): Define as UINT16_MAX.
        [!WCHAR_MAX] (WCHAR_MAX, WCHAR_MIN): Define.
        [!WINT_MAX] (WINT_MAX, WINT_MIN): Define.
libstdc++-v3 support:
        * configure.ac (AC_CONFIG_FILES): Add include/sys/Makefile.
        * include/Makefile.am (avr_HEADERS): Add fcntl.h, locale.h, unistd.h.
        (SUBDIRS): Add sys.
        * include/errno.h: Add definitions for error codes required to compile
        libstdc++-v3.
        * include/locale.h, include/unistd.h, include/fcntl.h: New files.
        * include/stdio.h (FILE): Change to a typedef.
        (BUFSIZ, _IONBF): Define.
        (fpos_t): Typedef.
        (fgetpos, fopen, freopen, fdopen, fseek, fsetpos, ftell): Prototype.
        (ftell, fileno, perror, remote, rename, rewind, setbuf): Likewise.
        (setvbuf, tmpfile, tmpnam): Likewise.
        * include/stdlib.h (atexit, system, getenv): Prototype.
        * include/string.h (strcoll, strerror, strxfrm): Prototype.
        * include/sys: New directory.
        * include/time.h (_CLOCKS_PER_SEC_): Declare.
        (CLOCKS_PER_SEC): Define.
        (clock): Declare.
        * libc/stdlib/Files.am (stdlib_a_c_sources): Add atexit.c, getenv.c,
        system.c
        * libc/stdlib/atexit.c: New file.
        * libc/stdlib/getenv.c, * libc/stdlib/system.c: New stub files.

This provides a bit of functionality, but mostly stubs, for hosted features
that we've been missing.  The alternative would be to make avr an outright
unhosted target, but that'd make it harder to test, and would also stop
using some applications that depend on minimal hosted features.
Provide a proper sqrtf declaration in math.h .
While we could have also get a functional header declaration using
__asm__ to make references use the sqrt symbol, it is preferable to
provide an actual sqrtf symbol in the library, so that code that
expects to be able to use sqrtf directly - like
gcc/gcc/testsuite/gcc.dg/pr41963.c - will work.

        * include/math.h (sqrtf): Don't #define, declare.
        * libm/fplib/asmdef.h (ALIAS_ENTRY): Define.
        * libm/fplib/sqrt.S (sqrtf): New ALIAS_ENTRY.
bug #41006: updated EFUSE_DEFAULT for atmega328p
        * include/Makefile.am (avr_HEADERS): Add signal.h .
        * include/signal.h: New file.
Update xmega wdt_enable to wait until SYNCBUSY bit is cleared. Add wdt_disable for xmega.
patch #8499: Device ata6289 is moved to avr4 architecture