[clang] [llvm] [NFC][PowerPC] Cleaning up test file and removing redundant front-end test (PR #151971)

[Tony Varghese via llvm-commits]

================
@@ -7,240 +8,87 @@
 ; RUN: llc -verify-machineinstrs -mcpu=pwr9 -mtriple=powerpc-ibm-aix \
 ; RUN:   < %s | FileCheck %s --check-prefix=POWERPC_32
 
-define i32 @test_Greater_than(ptr %colauths, i32 signext %ncols) {
-; This testcase is manually reduced to isolate the critical code blocks.
-; It is designed to check for vector comparison specifically for zero vectors.
-; In the vector.body section, we are expecting a comparison instruction (vcmpequh), 
-; merge instructions (vmrghh and vmrglh) which use exactly 2 vectors. 
----------------
tonykuttai wrote:

Add comment on what this test is locking down.

https://github.com/llvm/llvm-project/pull/151971