[x86] invpcid intrinsic

An intrinsic for an old instruction, as described in the Intel SDM.

Reviewers: craig.topper, rnk

Reviewed By: craig.topper, rnk

Differential Revision: https://reviews.llvm.org/D47142

llvm-svn: 333256
diff --git a/clang/test/Driver/x86-target-features.c b/clang/test/Driver/x86-target-features.c
index b7a1ead..515ca42 100644
--- a/clang/test/Driver/x86-target-features.c
+++ b/clang/test/Driver/x86-target-features.c
@@ -164,3 +164,8 @@
 // RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mno-ptwrite %s -### -o %t.o 2>&1 | FileCheck -check-prefix=NO-PTWRITE %s
 // PTWRITE: "-target-feature" "+ptwrite"
 // NO-PTWRITE: "-target-feature" "-ptwrite"
+
+// RUN: %clang -target i386-unknown-linux-gnu -march=i386 -minvpcid %s -### -o %t.o 2>&1 | FileCheck -check-prefix=INVPCID %s
+// RUN: %clang -target i386-unknown-linux-gnu -march=i386 -mno-invpcid %s -### -o %t.o 2>&1 | FileCheck -check-prefix=NO-INVPCID %s
+// INVPCID: "-target-feature" "+invpcid"
+// NO-INVPCID: "-target-feature" "-invpcid"