[clang][BPF] Turn on AddressSanitizer pass (#167766)

The BPF LLVM target currently doesn't support turning on the
AddressSanitizer pass, either for userspace ASAN or KASAN. Enable the
KASAN option for the BPF target in anticipation of a KASAN
implementation for BPF.

Author: etsal

clang/lib/Driver/ToolChain.cpp

@@ -1639,6 +1639,8 @@ SanitizerMask ToolChain::getSupportedSanitizers() const {
     Res |= SanitizerKind::ShadowCallStack;
   if (getTriple().isAArch64(64))
     Res |= SanitizerKind::MemTag;
+  if (getTriple().isBPF())
+    Res |= SanitizerKind::KernelAddress;
   return Res;
 }