[gcc r13-336] testsuite: Update Wconversion testcase check type.

[gcc r13-336] testsuite: Update Wconversion testcase check type.

[Palmer Dabbelt]

https://gcc.gnu.org/g:8585185cc4de3a9268af6afc42a0e86b7ba72b12

commit r13-336-g8585185cc4de3a9268af6afc42a0e86b7ba72b12
Author: jiawei <jiawei@iscas.ac.cn>
Date:   Thu May 5 18:33:20 2022 +0800

    testsuite: Update Wconversion testcase check type.
    
    Some compiler target like arm-linux\riscv\power\s390x\xtensa-gcc handle
    char as unsigned char, then there are no warnings occur and got FAIL cases.
    Just change the type char into explicit signed char to keep the feature
    consistency.
    
    gcc/testsuite/ChangeLog:
    
            * c-c++-common/Wconversion-1.c: Update type.

Diff:
---
 gcc/testsuite/c-c++-common/Wconversion-1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/testsuite/c-c++-common/Wconversion-1.c b/gcc/testsuite/c-c++-common/Wconversion-1.c
index ed65918c70f..81f9498d07c 100644
--- a/gcc/testsuite/c-c++-common/Wconversion-1.c
+++ b/gcc/testsuite/c-c++-common/Wconversion-1.c
@@ -10,5 +10,5 @@ void g()
   signed char sc = 300; /* { dg-warning "conversion from .int. to .signed char. changes value from .300. to .44." } */
   unsigned char uc = 300; /* { dg-warning "conversion from .int. to .unsigned char. changes value from .300. to .44." } */
   unsigned char uc2 = 300u; /* { dg-warning "conversion from .unsigned int. to .unsigned char. changes value from .300. to .44." } */
-  char c2 = (double)1.0 + 200; /* { dg-warning "overflow in conversion from .double. to .char. changes value from .2.01e\\+2. to .127." } */
+  signed char c2 = (double)1.0 + 200; /* { dg-warning "overflow in conversion from .double. to .signed char. changes value from .2.01e\\+2. to .127." } */
 }