Allow for custom address spaces

Julia uses addressspaces for GC and we want these to be sanitized as well.

(cherry picked from commit 3f53397)

Author: vchuravy

llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp

@@ -431,7 +431,9 @@ static bool shouldInstrumentReadWriteFromAddress(const Module *M, Value *Addr) {
   // with them.
   if (Addr) {
     Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
-    if (PtrTy->getPointerAddressSpace() != 0)
+    auto AS = PtrTy->getPointerAddressSpace();
+    // Allow for custom addresspaces
+    if (AS != 0 && AS < 10)
       return false;
   }