Add musl/ppc mcontext differences specific checks to choose
correct gregs and context structure definitions

Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>
--- a/sigsegv.c
+++ b/sigsegv.c
@@ -95,7 +95,11 @@ static void signal_segv(int signum, sigi
     for(i = 0; i < NGREG; i++)
         a2j_error("reg[%02d]       = 0x" REGFORMAT, i,
 #if defined(__powerpc__) && !defined(__powerpc64__)
+# if defined(__GLIBC__)
                 ucontext->uc_mcontext.uc_regs[i]
+# else
+                ucontext->uc_regs->gregs[i]
+# endif
 #elif defined(__powerpc64__)
                 ucontext->uc_mcontext.gp_regs[i]
 #elif defined(__sparc__) && defined(__arch64__)