[SveEmitter] Implement builtins for gathers/scatters

This patch adds builtins for:
  * regular, first-faulting and non-temporal gather loads
  * regular and non-temporal scatter stores

Differential Revision: https://reviews.llvm.org/D77735
diff --git a/clang/utils/TableGen/SveEmitter.cpp b/clang/utils/TableGen/SveEmitter.cpp
index 1e01f61..a32345e 100644
--- a/clang/utils/TableGen/SveEmitter.cpp
+++ b/clang/utils/TableGen/SveEmitter.cpp
@@ -481,6 +481,11 @@
     Signed = false;
     Float = false;
     break;
+  case 'x':
+    Predicate = false;
+    Signed = true;
+    Float = false;
+    break;
   case 'i':
     Predicate = false;
     Float = false;