Tweak code to make it easier to compile with gcc.
  + Use macros to name symbols with non-ASCII characters.
  + Make some variables unsigned, because they are compared
    against unsigned values.
  + Fix a few void* pointers to be MLink*.

R=rsc
DELTA=94  (44 added, 3 deleted, 47 changed)
OCL=22303
CL=22638
diff --git a/src/runtime/mem.c b/src/runtime/mem.c
index 8e7a472..9d6a396 100644
--- a/src/runtime/mem.c
+++ b/src/runtime/mem.c
@@ -29,7 +29,7 @@
 {
 	byte *v;
 
-	v = sys·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, 0, 0);
+	v = sys_mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, 0, 0);
 	m->mem.nmmap += n;
 	return v;
 }
@@ -61,10 +61,10 @@
 			// hunk, and then once brk returned we'd immediately
 			// overwrite that hunk with our own.
 			// (the net result would be a memory leak, not a crash.)
-			// so we have to call sys·mmap directly - it is written
+			// so we have to call sys_mmap directly - it is written
 			// in assembly and tagged not to grow the stack.
 			m->mem.hunk =
-				sys·mmap(nil, NHUNK, PROT_READ|PROT_WRITE,
+				sys_mmap(nil, NHUNK, PROT_READ|PROT_WRITE,
 					MAP_ANON|MAP_PRIVATE, 0, 0);
 			m->mem.nhunk = NHUNK;
 			m->mem.nmmap += NHUNK;
@@ -78,7 +78,7 @@
 }
 
 void
-sys·mal(uint32 n, uint8 *ret)
+sys_mal(uint32 n, uint8 *ret)
 {
 	ret = mal(n);
 	FLUSH(&ret);