[MVE] Rename of tests making them consistent with tail-predication tests. NFC.

Author: Sjoerd Meijer

llvm/test/CodeGen/Thumb2/LowOverheadLoops/basic-tail-pred.ll renamed to llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-basic.ll

@@ -1,4 +1,3 @@
-; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: opt -mtriple=thumbv8.1m.main -mve-tail-predication -tail-predication=enabled -mattr=+mve,+lob %s -S -o - | FileCheck %s
 
 ; CHECK-LABEL: mul_v16i8

llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-reduce.ll renamed to llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-reduce.ll

@@ -135,8 +135,9 @@ for.cond.cleanup:
 }
 
 ; The vector loop is not guarded with an entry check (N == 0). Check that
-; despite this we can still calculate a precise enough range for the
-; backedge count to safely insert a vctp here.
+; despite this we can still calculate a precise enough range so that the
+; the overflow checks for get.active.active.lane.mask don't reject
+; tail-predication.
 ;
 ; CHECK-LABEL: @reduction_not_guarded
 ;