[llvm] [RISC-V][ISel] Remove redundant czero.eqz like 'czero.eqz a0, a0, a0' (PR #90208)

[Zhijin Zeng via llvm-commits]

zengdage wrote:

Sorry, is anyone know why the CI buildkite failed ? I can't run the build command `./.ci/monolithic-linux.sh "bolt;clang;clang-tools-extra;flang;lld;llvm;mlir;polly" "check-bolt check-clang check-clang-tools check-flang check-lld check-llvm check-mlir check-polly"` in my pc, and don't understand the error log as follow: 

```
FAIL: BOLT :: RISCV/unnamed-sym-no-entry.c (55 of 431)

******************** TEST 'BOLT :: RISCV/unnamed-sym-no-entry.c' FAILED ********************
Exit Code: 1
Command Output (stderr):
RUN: at line 6: /usr/bin/clang  --target=x86_64-linux -fuse-ld=lld -Wl,--unresolved-symbols=ignore-all --target=riscv64 -nostdlib -ffreestanding -Wl,--emit-relocs -g -Wl,-q -o /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/tools/bolt/test/RISCV/Output/unnamed-sym-no-entry.c.tmp /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/bolt/test/RISCV/unnamed-sym-no-entry.c

+ /usr/bin/clang --target=x86_64-linux -fuse-ld=lld -Wl,--unresolved-symbols=ignore-all --target=riscv64 -nostdlib -ffreestanding -Wl,--emit-relocs -g -Wl,-q -o /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/tools/bolt/test/RISCV/Output/unnamed-sym-no-entry.c.tmp /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/bolt/test/RISCV/unnamed-sym-no-entry.c

/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/bin/llvm-readelf -s /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/tools/bolt/test/RISCV/Output/unnamed-sym-no-entry.c.tmp | /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/bin/FileCheck /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/bolt/test/RISCV/unnamed-sym-no-entry.c --check-prefix=CHECK-ELF

/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/bin/FileCheck /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/bolt/test/RISCV/unnamed-sym-no-entry.c --check-prefix=CHECK-ELF

/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/bin/llvm-readelf -s /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/build/tools/bolt/test/RISCV/Output/unnamed-sym-no-entry.c.tmp

/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/bolt/test/RISCV/unnamed-sym-no-entry.c:11:19: error: CHECK-ELF-DAG: expected string not found in input

CHECK-ELF-DAG: [[#%x,START]] {{.*}} NOTYPE LOCAL DEFAULT [[#SECTION]] .L0 {{$}}

^
<stdin>:1:1: note: scanning from here

<stdin>:1:1: note: with "%x,START" equal to "11120"

<stdin>:1:1: note: with "SECTION" equal to "1"

<stdin>:4:20: note: possible intended match here

0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND 
Input file: <stdin>

Check file: /var/lib/buildkite-agent/builds/linux-56-59b8f5d88-6mhbj-1/llvm-project/github-pull-requests/bolt/test/RISCV/unnamed-sym-no-entry.c

-dump-input=help explains the following input dump.

Input was:
<<<<<<
1:  
dag:11'0     X error: no match found
dag:11'1      with "%x,START" equal to "11120"
dag:11'2       with "SECTION" equal to "1"
2: Symbol table '.symtab' contains 32 entries: 
dag:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3:  Num: Value Size Type Bind Vis Ndx Name 
dag:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4:  0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND  
dag:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
dag:11'3                        ?                              possible intended match
5:  1: 0000000000000000 0 FILE LOCAL DEFAULT ABS unnamed-sym-no-entry.c 
dag:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
6:  2: 0000000000011120 0 NOTYPE LOCAL DEFAULT 1  
11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7:  3: 0000000000011120 0 NOTYPE LOCAL DEFAULT 1  
dag:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8:  4: 0000000000011120 0 NOTYPE LOCAL DEFAULT 1  
dag:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9:  5: 0000000000011122 0 NOTYPE LOCAL DEFAULT 1  
dag:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
********************
```

https://github.com/llvm/llvm-project/pull/90208