Only test issue-101082.rs#x86-64-v3 on our bundled LLVM

Author: cuviper

tests/codegen/issues/issue-101082.rs

@@ -2,7 +2,8 @@
 //@ revisions: host x86-64-v3
 //@ min-llvm-version: 20
 
-// This particular CPU regressed in #131563
+// This particular CPU regressed in #131563, and remains fickle with different LLVM
+//@[x86-64-v3] no-system-llvm
 //@[x86-64-v3] only-x86_64
 //@[x86-64-v3] compile-flags: -Ctarget-cpu=x86-64-v3