Revert "Temporary move __udivdi3 back to LIBC for x86"

This reverts commit bc02fb964a59983521c5f6cf80b1189434952780.

Bug: http://b/26406724
Bug: http://b/26423217
Change-Id: I8e3186fc76502d6818753e5d76a7c145207ed9a3
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 4d06c52..d2e2b1b 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -223,7 +223,6 @@
     __timer_getoverrun; # arm x86 mips
     __timer_gettime; # arm x86 mips
     __timer_settime; # arm x86 mips
-    __udivdi3; # x86
     __umask_chk;
     __vsnprintf_chk;
     __vsprintf_chk;
@@ -1456,7 +1455,7 @@
     __system_property_update; # arm64 x86_64 mips64
     __system_property_wait_any; # arm64 x86_64 mips64
     __truncdfsf2; # arm
-    __udivdi3; # arm mips
+    __udivdi3; # arm x86 mips
     __udivsi3; # arm
     __umoddi3; # x86 mips
     __unorddf2; # arm