bug#34277: Error after dump complete when build on Windows 10

[Eli Zaretskii <eliz@gnu.org>]

> From: "Shuguang Sun" <shuguang79@qq.com>
> Date: Sat, 2 Feb 2019 20:44:02 +0800
> 
> Thread 1 received signal SIGSEGV, Segmentation fault.
> 0x00007ffaa8859f60 in ntdll!RtlAllocateHeap ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> (gdb) thread 1
> [Switching to thread 1 (Thread 123272.0x517c)]
> #0  0x00007ffaa8859f60 in ntdll!RtlAllocateHeap ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> (gdb) backtrace
> #0  0x00007ffaa8859f60 in ntdll!RtlAllocateHeap ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #1  0x00007ffa64506ef8 in NotifyShims ()
>    from C:\WINDOWS\AppPatch\AppPatch64\AcLayers.dll
> #2  0x00000004001b72d7 in malloc_before_dump (size=<optimized out>)
>     at w32heap.c:376
> #3  0x0000000400100961 in lmalloc (size=56) at alloc.c:1486
> #4  xmalloc (size=size@entry=56) at alloc.c:892
> #5  0x00000004001ab4ec in GetCachedVolumeInformation (
>     root_dir=<optimized out>) at w32.c:3303
> #6  get_volume_info (
>     name=name@entry=0xbff890 "C:\\gitemacs\\emacs\\src\\bootstrap-emacs.pdmp",
> pPath=pPath@entry=0xbff0f8) at w32.c:3353
> #7  0x00000004001ad5af in is_fat_volume (pPath=0xbff0f8,
>     name=0xbff890 "C:\\gitemacs\\emacs\\src\\bootstrap-emacs.pdmp")
>     at w32.c:3369
> #8  map_w32_filename (
>     name=name@entry=0xbff890 "C:\\gitemacs\\emacs\\src\\bootstrap-emacs.pdmp",
> pPath=pPath@entry=0x0) at w32.c:3396
> #9  0x00000004001ae5bc in sys_open (
>     path=path@entry=0xbff890 "C:\\gitemacs\\emacs\\src\\bootstrap-emacs.pdmp",
> oflag=oflag@entry=32896, mode=mode@entry=0) at w32.c:4461
> #10 0x00000004000c138a in emacs_open (
>     file=file@entry=0xbff890 "C:\\gitemacs\\emacs\\src\\bootstrap-emacs.pdmp", oflags=32896,
> oflags@entry=0, mode=mode@entry=0) at sysdep.c:2472
> #11 0x000000040010a2e6 in pdumper_load (
>     dump_filename=0xbff890 "C:\\gitemacs\\emacs\\src\\bootstrap-emacs.pdmp")
>     at pdumper.c:5410

Thanks, I think I fixed this.  Please try the latest master branch.