[X86] Add TSXLDTRK instructions.

Summary: For more details about these instructions, please refer to the latest ISE document: https://software.intel.com/en-us/download/intel-architecture-instruction-set-extensions-programming-reference

Reviewers: craig.topper, RKSimon, LuoYuanke

Reviewed By: craig.topper

Subscribers: mgorny, hiraditya, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77205
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
index 511f314..e5a6497 100644
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -3175,6 +3175,8 @@
 
 .. option:: -mtbm, -mno-tbm
 
+.. option:: -mtsxldtrk, -mno-tsxldtrk
+
 .. option:: -mvaes, -mno-vaes
 
 .. option:: -mvpclmulqdq, -mno-vpclmulqdq