stdbool tests: Avoid compilation error with Sun C on Solaris 10

[Bruno Haible]

On Solaris 10/SPARC with Sun C 5.8, I get this compilation error:

cc -D_STDC_C99= -xarch=generic64 -O -DHAVE_CONFIG_H -DEXEEXT=\"\" -DEXEEXT=\"\" 
-I. -I../../gltests -I..  -DGNULIB_STRICT_CHECKING=1  -DIN_GNULIB_TESTS=1  -I. 
-I../../gltests  -I.. -I../../gltests/..  -I../gllib -I../../gltests/../gllib  
-I/home/haible/prefix-sparc64/include -D_REENTRANT  -g -c -o test-stdbool-c99.o 
../../gltests/test-stdbool-c99.c
"../../gltests/test-stdbool.c", line 64: zero or negative subscript
"../../gltests/test-stdbool.c", line 100: warning: improper pointer/integer 
combination: op "="
cc: acomp failed for ../../gltests/test-stdbool-c99.c
*** Error code 2

This patch avoids the compilation error.


2023-04-28  Bruno Haible  <bruno@clisp.org>

        stdbool tests: Avoid compilation error with Sun C on Solaris 10.
        * tests/test-stdbool.c (WORKING_BOOL): Set to 0 on Sun C.

diff --git a/tests/test-stdbool.c b/tests/test-stdbool.c
index 6ca9535e87..a4ff4d4b53 100644
--- a/tests/test-stdbool.c
+++ b/tests/test-stdbool.c
@@ -48,7 +48,7 @@
    least, not for all compilers and compiler options.  */
 #if ((HAVE_C_BOOL || defined __cplusplus \
       || HAVE_STDBOOL_H || 3 <= __GNUC__ || 4 <= __clang_major__) \
-     && !defined _MSC_VER)
+     && !(defined _MSC_VER || defined __SUNPRO_C))
 # define WORKING_BOOL 1
 #else
 # define WORKING_BOOL 0