Check for GCC -Warray-bounds checking that LLVM has

example:

int main(int argc, char **argv) {

    int array[5] = {1,2,3,4,5};
    int x = array[10];
    
    return 0;
}

Compiling with GCC-master:

philbert@philbert-beast {~/workspace/gccrs-build} $ gcc -g -O0 -Wall test.c -o test
test.c: In function ‘main’:
test.c:4:9: warning: unused variable ‘x’ [-Wunused-variable]
    4 |     int x = array[10];
      |         ^

Compiling with clang:

philbert@philbert-beast {~/workspace/gccrs-build} $ clang -g -O0 -Wall test.c -o test
test.c:4:9: warning: unused variable 'x' [-Wunused-variable]
    int x = array[10];
        ^
test.c:4:13: warning: array index 10 is past the end of the array (which contains 5 elements) [-Warray-bounds]
    int x = array[10];
            ^     ~~
test.c:3:5: note: array 'array' declared here
    int array[5] = {1,2,3,4,5};
    ^
2 warnings generated.

Start by reproducing the standalone C example with GCC and Clang using the commands and source shown in the issue, then locate the compiler diagnostics and array-bounds checking implementation. Done means GCC reports an equivalent out-of-bounds warning for the example; the issue names no source files or tests to begin with.