Remove duplicates from defined-symbols.txt

In WebAssembly#311, it became apparent that duplicate symbol definitions were
becoming unwieldy. This change merges all duplicates using `uniq`.

Author: abrown

Makefile

@@ -527,7 +527,7 @@ check-symbols: startup_files libc
 	@# Ignore certain llvm builtin symbols such as those starting with __mul
 	@# since these dependencies can vary between llvm versions.
 	"$(NM)" --defined-only "$(SYSROOT_LIB)"/libc.a "$(SYSROOT_LIB)"/libwasi-emulated-*.a "$(SYSROOT_LIB)"/*.o \
-	    |grep ' [[:upper:]] ' |sed 's/.* [[:upper:]] //' |LC_ALL=C sort > "$(DEFINED_SYMBOLS)"
+	    |grep ' [[:upper:]] ' |sed 's/.* [[:upper:]] //' |LC_ALL=C sort |uniq > "$(DEFINED_SYMBOLS)"
 	for undef_sym in $$("$(NM)" --undefined-only "$(SYSROOT_LIB)"/libc.a "$(SYSROOT_LIB)"/libc-*.a "$(SYSROOT_LIB)"/*.o \
 	    |grep ' U ' |sed 's/.* U //' |LC_ALL=C sort |uniq); do \
 	    grep -q '\<'$$undef_sym'\>' "$(DEFINED_SYMBOLS)" || echo $$undef_sym; \

expected/wasm32-wasi/defined-symbols.txt

@@ -37,9 +37,6 @@ __des_setkey
 __do_des
 __duplocale
 __env_rm_add
-__env_rm_add
-__env_rm_add
-__env_rm_add
 __exp2f_data
 __exp_data
 __expo2
@@ -70,8 +67,6 @@ __fsmu8
 __ftello
 __ftello_unlocked
 __funcs_on_exit
-__funcs_on_exit
-__funcs_on_quick_exit
 __funcs_on_quick_exit
 __futimesat
 __fwritable
@@ -127,7 +122,6 @@ __isxdigit_l
 __lctrans
 __lctrans_cur
 __lctrans_impl
-__lctrans_impl
 __ldexp_cexp
 __ldexp_cexpf
 __lgamma_r
@@ -199,22 +193,16 @@ __sinl
 __small_printf
 __stderr_FILE
 __stderr_used
-__stderr_used
-__stderr_used
 __stdin_FILE
 __stdin_used
-__stdin_used
 __stdio_close
 __stdio_exit
-__stdio_exit
 __stdio_exit_needed
 __stdio_read
 __stdio_seek
 __stdio_write
 __stdout_FILE
 __stdout_used
-__stdout_used
-__stdout_used
 __stdout_write
 __stpcpy
 __stpncpy
@@ -310,7 +298,6 @@ __wasilibc_deinitialize_environ
 __wasilibc_dttoif
 __wasilibc_ensure_environ
 __wasilibc_environ
-__wasilibc_environ
 __wasilibc_fd_renumber
 __wasilibc_find_abspath
 __wasilibc_find_relpath
@@ -322,7 +309,6 @@ __wasilibc_link
 __wasilibc_link_newat
 __wasilibc_link_oldat
 __wasilibc_maybe_reinitialize_environ_eagerly
-__wasilibc_maybe_reinitialize_environ_eagerly
 __wasilibc_nocwd___wasilibc_rmdirat
 __wasilibc_nocwd___wasilibc_unlinkat
 __wasilibc_nocwd_faccessat
@@ -359,7 +345,6 @@ _exit
 _flushlbf
 _initialize
 _start
-_start
 a64l
 abort
 abs