link with libatomic

This fixes build with C11

lib/../Source/WTF/wtf/CMakeFiles/WTF.dir/Assertions.cpp.o:/usr/include/c++/11.0.1/bits/atomic_base.h:520: more undefined references to `__atomic_compare_exchange_1' follow
| collect2: error: ld returned 1 exit status

Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>

--- a/Source/WTF/wtf/CMakeLists.txt
+++ b/Source/WTF/wtf/CMakeLists.txt
@@ -245,6 +245,10 @@ if (NOT USE_SYSTEM_MALLOC)
     list(APPEND WTF_LIBRARIES bmalloc)
 endif ()
 
+list(APPEND WTF_LIBRARIES
+     -Wl,--as-needed -Wl,-latomic -Wl,--no-as-needed
+)
+
 list(APPEND WTF_SOURCES
     unicode/icu/CollatorICU.cpp
 )