Rename os_total_mem to os_get_total_mem_kib.

Also removed an unused parameter.

src/option.c

@@ -2029,7 +2029,7 @@ void set_init_1(void)
     {
 #ifdef HAVE_TOTAL_MEM
       /* Use amount of memory available to Vim. */
-      n = (os_total_mem(FALSE) >> 1);
+      n = (os_get_total_mem_kib() >> 1);
 #else
       n = (0x7fffffff >> 11);
 #endif

src/os/mem.c

@@ -1,13 +1,10 @@
-// os.c -- OS-level calls to query hardware, etc.
+/// Functions for accessing system memory information.
 
 #include <uv.h>
 
 #include "os/os.h"
 
-// Return total amount of memory available in Kbyte.
-// Doesn't change when memory has been allocated.
-long_u os_total_mem(int special) {
-  // We need to return memory in *Kbytes* but uv_get_total_memory() returns the
-  // number of bytes of total memory.
+long_u os_get_total_mem_kib(void) {
+  // Convert bytes to KiB.
   return uv_get_total_memory() >> 10;
 }

src/os/os.h

@@ -78,7 +78,8 @@ int os_rmdir(const char *path);
 /// @return `0` for success, non-zero for failure.
 int os_remove(const char *path);
 
-long_u os_total_mem(int special);
+/// Get the total system physical memory in KiB.
+long_u os_get_total_mem_kib(void);
 const char *os_getenv(const char *name);
 int os_setenv(const char *name, const char *value, int overwrite);
 char *os_getenvname_at_index(size_t index);