rename superh port to "sh" for consistency

linux, gcc, etc. all use "sh" as the name for the superh arch. there
was already some inconsistency internally in musl: the dynamic linker
was searching for "ld-musl-sh.path" as its path file despite its own
name being "ld-musl-superh.so.1". there was some sentiment in both
directions as to how to resolve the inconsistency, but overall "sh"
was favored.

arch/sh/bits/fcntl.h

@@ -0,0 +1,39 @@
+#define O_CREAT        0100
+#define O_EXCL         0200
+#define O_NOCTTY       0400
+#define O_TRUNC       01000
+#define O_APPEND      02000
+#define O_NONBLOCK    04000
+#define O_DSYNC      010000
+#define O_SYNC     04010000
+#define O_RSYNC    04010000
+#define O_DIRECTORY 0200000
+#define O_NOFOLLOW  0400000
+#define O_CLOEXEC  02000000
+
+#define O_ASYNC      020000
+#define O_DIRECT     040000
+#define O_LARGEFILE 0100000
+#define O_NOATIME  01000000
+#define O_TMPFILE 020200000
+#define O_NDELAY O_NONBLOCK
+
+#define F_DUPFD  0
+#define F_GETFD  1
+#define F_SETFD  2
+#define F_GETFL  3
+#define F_SETFL  4
+
+#define F_SETOWN 8
+#define F_GETOWN 9
+#define F_SETSIG 10
+#define F_GETSIG 11
+
+#define F_GETLK 12
+#define F_SETLK 13
+#define F_SETLKW 14
+
+#define F_SETOWN_EX 15
+#define F_GETOWN_EX 16
+
+#define F_GETOWNER_UIDS 17