Remove declaration for putw(3)/getw(3).

These were both removed from POSIX 2004, and we don't define an
implementation for getw(3). Keep the definition of put(3) on LP32 for
binary compatibility.

Bug: 13935372
Change-Id: Iba384b45093ac6d2d7c2d81f7980cd7701dd6f56

tests/stdio_test.cpp

@@ -531,10 +531,6 @@ TEST(stdio, cantwrite_EBADF) {
   EXPECT_EQ(EBADF, errno);
 #endif
 
-  errno = 0;
-  EXPECT_EQ(EOF, putw(1234, fp));
-  EXPECT_EQ(EBADF, errno);
-
   errno = 0;
   EXPECT_EQ(0U, fwrite("hello", 1, 2, fp));
   EXPECT_EQ(EBADF, errno);