Replace implementation of warn*/err*.

This eliminates a large number of warnings about incompatible function pointer
casts when compiling for asm.js.

Author: waywardmonkeys

emcc

@@ -1441,20 +1441,15 @@ try:
         'dlmalloc.c',
         os.path.join('libcxx', 'new.cpp'),
         os.path.join('libc', 'stdlib', 'getopt_long.c'),
-        os.path.join('libc', 'gen', 'err.c'),
-        os.path.join('libc', 'gen', 'errx.c'),
-        os.path.join('libc', 'gen', 'warn.c'),
-        os.path.join('libc', 'gen', 'warnx.c'),
-        os.path.join('libc', 'gen', 'verr.c'),
-        os.path.join('libc', 'gen', 'verrx.c'),
-        os.path.join('libc', 'gen', 'vwarn.c'),
-        os.path.join('libc', 'gen', 'vwarnx.c'),
       ]
       musl_files = [
         ['internal', [
          'floatscan.c',
          'shgetc.c',
         ]],
+        ['legacy', [
+         'err.c',
+        ]],
         ['math', [
          'scalbn.c',
          'scalbnl.c',

system/lib/libc.symbols

@@ -49,19 +49,11 @@
          T __toread
          T __towrite
          T __uflow
-         T _err
-         T _errx
-         T _verr
-         T _verrx
-         T _vwarn
-         T _vwarnx
-         T _warn
-         T _warnx
          T atof
          W bulk_free
          W calloc
-         W err
-         W errx
+         T err
+         T errx
          W free
          T getopt
          T getopt_long
@@ -97,9 +89,9 @@
          T strtold
          W strtold_l
          W valloc
-         W verr
-         W verrx
-         W vwarn
-         W vwarnx
-         W warn
-         W warnx
+         T verr
+         T verrx
+         T vwarn
+         T vwarnx
+         T warn
+         T warnx