Fix console input on Windows to permit the debugger to function.

Previously, on Win32 with MSVC, the non-blocking input function didn't work correctly and prevented use of the debugger.  Instead, use native console I/O to implement non-blocking input, which both works and avoids CRT (i.e. MSVC vs. Cygwin) dependency.

src/dis.c

@@ -392,6 +392,7 @@ do_debug_intfc()
 				show_regs();
 				break;
 			case '\n':
+			case '\r':
 				*line_ptr = 0;
 				if(old_mode == 's') {
 					do_blank();
@@ -720,7 +721,7 @@ read_line(char *buf, int len)
 			break;
 		}
 		space_left -= ret;
-		if(buf[ret-1] == 0x0a) {
+		if(buf[ret-1] == '\r' || buf[ret-1] == '\n') {
 			break;
 		}
 		buf = &buf[ret];

src/win_console.c

@@ -41,18 +41,20 @@ extern int  g_win_fullscreen_state;
 int
 win_nonblock_read_stdin(int fd, char *bufptr, int len)
 {
-	HANDLE	oshandle;
-	DWORD	dwret;
-	int	ret;
-
-	errno = EAGAIN;
-	oshandle = (HANDLE)_get_osfhandle(fd);	// get stdin handle
-	dwret = WaitForSingleObject(oshandle, 1);	// wait 1msec for data
-	ret = -1;
-	if(dwret == WAIT_OBJECT_0) {
-		ret = read(fd, bufptr, len);
+	DWORD charsRead = 0;
+	ReadConsole(GetStdHandle(STD_INPUT_HANDLE), bufptr, len, &charsRead, NULL);
+	
+	if (charsRead == 0)
+	{
+		errno = EAGAIN;
+		return -1;
+	}
+	else
+	{
+		DWORD charsWritten = 0;
+		WriteConsole(GetStdHandle(STD_OUTPUT_HANDLE), bufptr, charsRead, &charsWritten, NULL);
+		return charsRead;
 	}
-	return ret;
 }
 
 void get_cwd(LPTSTR buffer, int size)
@@ -166,6 +168,14 @@ main(int argc, char **argv)
 	printf("...rect is: %ld, %ld, %ld, %ld\n", rect.left, rect.top,
 		rect.right, rect.bottom);
 	
+	// Enable non-blocking, character-at-a-time console I/O.
+	// win_nonblock_read_stdin() expects this behavior.
+	DWORD mode;
+	GetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), &mode);
+	mode &= ~ENABLE_LINE_INPUT;
+	SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), mode);
+
+
 	gsportinit(hwnd);
 	int ret =  gsportmain(argc, argv);