Fix bootstrap bug

core/io/streams/c/c-tests.factor

@@ -0,0 +1,10 @@
+USING: tools.test io.files io io.streams.c ;
+IN: temporary
+
+[ "hello world" ] [
+    "test.txt" resource-path <file-writer> [
+        "hello world" write
+    ] with-stream
+
+    "test.txt" resource-path "rb" fopen <c-reader> contents
+] unit-test

core/io/streams/c/c.factor

@@ -29,6 +29,9 @@ C: <c-reader> c-reader
 M: c-reader stream-read
     >r >fixnum r> c-reader-handle fread ;
 
+M: c-reader stream-read-partial
+    stream-read ;
+
 M: c-reader stream-read1
     c-reader-handle fgetc ;