fix build on P9 (#739)
diff --git a/absl/random/internal/randen_hwaes.cc b/absl/random/internal/randen_hwaes.cc
index 9966486..b5a3f90 100644
--- a/absl/random/internal/randen_hwaes.cc
+++ b/absl/random/internal/randen_hwaes.cc
@@ -150,6 +150,7 @@
#include <altivec.h>
// <altivec.h> #defines vector __vector; in C++, this is bad form.
#undef vector
+#undef bool
// Rely on the PowerPC AltiVec vector operations for accelerated AES
// instructions. GCC support of the PPC vector types is described in:
