Use standards compliant header locations

Use signal.h instead of sys/signal.h and poll.h instead of sys/poll.h
to fix building against musl libc.

Bug: 190084016
Test: m USE_HOST_MUSL=true host-native
Change-Id: I41945f1b9414ceea7390f3eb5fbbac464f57c14e
diff --git a/src/solaris/javavm/export/jvm_md.h b/src/solaris/javavm/export/jvm_md.h
index 5c68191..62415ee 100644
--- a/src/solaris/javavm/export/jvm_md.h
+++ b/src/solaris/javavm/export/jvm_md.h
@@ -65,7 +65,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <errno.h>
-#include <sys/signal.h>
+#include <signal.h>
 
 /* O Flags */
 
diff --git a/src/solaris/transport/socket/socket_md.c b/src/solaris/transport/socket/socket_md.c
index 33e062e..819fcab 100644
--- a/src/solaris/transport/socket/socket_md.c
+++ b/src/solaris/transport/socket/socket_md.c
@@ -37,7 +37,7 @@
 #include <thread.h>
 #else
 #include <pthread.h>
-#include <sys/poll.h>
+#include <poll.h>
 #endif
 
 #include "socket_md.h"