linux-user: Add HPPA target_signal.h and target_cpu.h

The cpu.h structure that these manipulate hasn't been defined
yet, but we haven't enabled compilation yet either.
Signed-off-by: NRichard Henderson <rth@twiddle.net>

linux-user/hppa/target_cpu.h

+/*
+ * HPPA specific CPU ABI and functions for linux-user
+ *
+ *  Copyright (c) 2016  Richard Henderson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef ALPHA_TARGET_CPU_H
+#define ALPHA_TARGET_CPU_H
+
+static inline void cpu_clone_regs(CPUHPPAState *env, target_ulong newsp)
+{
+    if (newsp) {
+        env->gr[30] = newsp;
+    }
+    env->gr[28] = 0;
+}
+
+static inline void cpu_set_tls(CPUHPPAState *env, target_ulong newtls)
+{
+    env->cr27 = newtls;
+}
+
+#endif

linux-user/hppa/target_signal.h

+#ifndef HPPA_TARGET_SIGNAL_H
+#define HPPA_TARGET_SIGNAL_H
+
+#include "cpu.h"
+
+/* this struct defines a stack used during syscall handling */
+
+typedef struct target_sigaltstack {
+    abi_ulong ss_sp;
+    int32_t ss_flags;
+    abi_ulong ss_size;
+} target_stack_t;
+
+
+/*
+ * sigaltstack controls
+ */
+#define TARGET_SS_ONSTACK	1
+#define TARGET_SS_DISABLE	2
+
+#define TARGET_MINSIGSTKSZ	2048
+#define TARGET_SIGSTKSZ		8192
+
+static inline abi_ulong get_sp_from_cpustate(CPUHPPAState *state)
+{
+    return state->gr[30];
+}
+
+#endif /* HPPA_TARGET_SIGNAL_H */