win32: update sysinfo(2) implementation

Add a call to GetPerformanceInfo.  Treat the SystemCache member of
the PERFORMANCE_INFORMATION structure as buffer RAM.  Deduct it
from available RAM.

The numbers reported by 'free' move about in vaguely sensible
ways when I start and stop programs, though I still don't know
if they're in any way accurate.

1 files changed, 0 insertions, 2 deletions

diff --git a/include/mingw.h b/include/mingw.h
index c2a8b61bf..5cb5cb88c 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -364,8 +364,6 @@ struct sysinfo {
         unsigned long totalhigh; /* Total high memory size */
         unsigned long freehigh;  /* Available high memory size */
         unsigned int mem_unit;   /* Memory unit size in bytes */
-        char _f[20-2*sizeof(long)-sizeof(int)];
-        /* Padding to 64 bytes */
 };
 
 int sysinfo(struct sysinfo *info);