[LoongArch][Clang] Make the parameters and return value of {x,}vxor.v builtins unsigned char vectors

The lsxintrin.h and and lasxintrin.h headers uses `unsigned char`
vectors instead of `signed char` vectors.  GCC also uses `unsigned char`
for them, so align their definition with the headers and GCC.

Fixes llvm#110834.

Author: xry111

clang/include/clang/Basic/BuiltinsLoongArchLASX.def

@@ -368,7 +368,7 @@ TARGET_BUILTIN(__builtin_lasx_xvrepli_d, "V4LLiIi", "nc", "lasx")
 
 TARGET_BUILTIN(__builtin_lasx_xvand_v, "V32UcV32UcV32Uc", "nc", "lasx")
 TARGET_BUILTIN(__builtin_lasx_xvor_v, "V32UcV32UcV32Uc", "nc", "lasx")
-TARGET_BUILTIN(__builtin_lasx_xvxor_v, "V32ScV32ScV32Sc", "nc", "lasx")
+TARGET_BUILTIN(__builtin_lasx_xvxor_v, "V32UcV32UcV32Uc", "nc", "lasx")
 TARGET_BUILTIN(__builtin_lasx_xvnor_v, "V32UcV32UcV32Uc", "nc", "lasx")
 TARGET_BUILTIN(__builtin_lasx_xvandn_v, "V32UcV32UcV32Uc", "nc", "lasx")
 TARGET_BUILTIN(__builtin_lasx_xvorn_v, "V32ScV32ScV32Sc", "nc", "lasx")

clang/include/clang/Basic/BuiltinsLoongArchLSX.def

@@ -352,7 +352,7 @@ TARGET_BUILTIN(__builtin_lsx_vrepli_d, "V2LLiIi", "nc", "lsx")
 
 TARGET_BUILTIN(__builtin_lsx_vand_v, "V16UcV16UcV16Uc", "nc", "lsx")
 TARGET_BUILTIN(__builtin_lsx_vor_v, "V16UcV16UcV16Uc", "nc", "lsx")
-TARGET_BUILTIN(__builtin_lsx_vxor_v, "V16ScV16ScV16Sc", "nc", "lsx")
+TARGET_BUILTIN(__builtin_lsx_vxor_v, "V16UcV16UcV16Uc", "nc", "lsx")
 TARGET_BUILTIN(__builtin_lsx_vnor_v, "V16UcV16UcV16Uc", "nc", "lsx")
 TARGET_BUILTIN(__builtin_lsx_vandn_v, "V16UcV16UcV16Uc", "nc", "lsx")
 TARGET_BUILTIN(__builtin_lsx_vorn_v, "V16ScV16ScV16Sc", "nc", "lsx")