Update global_symbols.txt.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@375284 91177308-0d34-0410-b5e6-96231b3b80d8

lib/sanitizer_common/symbolizer/scripts/global_symbols.txt

diff --git a/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt b/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
index 124a26b..fa42e2a 100644
--- a/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
+++ b/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
@@ -75,6 +75,7 @@
 getrlimit U
 gettimeofday U
 ioctl U
+isalnum U
 isalpha U
 isatty U
 islower U