libc changes: unify c and libc types; Add [^]T where appropriate

core/runtime/procs_windows_amd64.odin

@@ -1,3 +1,4 @@
+//+private
 package runtime
 
 foreign import kernel32 "system:Kernel32.lib"
@@ -51,19 +52,14 @@ memmove :: proc "c" (dst, src: rawptr, len: int) -> rawptr {
 }
 
 // @(link_name="memset")
-memset :: proc "c" (ptr: rawptr, val: i32, len: int) -> rawptr {
-	if ptr == nil || len == 0 {
-		return ptr
+memset :: proc "c" (ptr: rawptr, val: i32, len: int) -> rawptr #no_bounds_check {
+	if ptr != nil && len != 0 {
+		b := byte(val)
+		p := ([^]byte)(ptr)[:len]
+		for v in &p {
+			v = b
+		}
 	}
-
-	b := byte(val)
-
-	p_start := uintptr(ptr)
-	p_end := p_start + uintptr(max(len, 0))
-	for p := p_start; p < p_end; p += 1 {
-		(^byte)(p)^ = b
-	}
-
 	return ptr
 }