[X86] Support Intel avxvnni
This patch mainly made the following changes:
1. Support AVX-VNNI instructions;
2. Introduce ExplicitVEXPrefix flag so that vpdpbusd/vpdpbusds/vpdpbusds/vpdpbusds instructions only use vex-encoding when user explicity add {vex} prefix.
Differential Revision: https://reviews.llvm.org/D89105
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
index 0dca391..830d3ae 100644
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -3253,6 +3253,8 @@
.. option:: -mavx512vpopcntdq, -mno-avx512vpopcntdq
+.. option:: -mavxvnni, -mno-avxvnni
+
.. option:: -mbmi, -mno-bmi
.. option:: -mbmi2, -mno-bmi2