semihosting: move semihosting tests to multiarch

It may be arm-compat-semihosting but more than one architecture uses
it so lets move the tests into the multiarch area. We gate it on the
feature and split the semicall.h header between the arches.

Also clean-up a bit of the Makefile messing about to one common set of
runners.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210323165308.15244-6-alex.bennee@linaro.org>

tests/tcg/multiarch/arm-compat-semi/semihosting.c

@@ -0,0 +1,29 @@
+/*
+ * linux-user semihosting checks
+ *
+ * Copyright (c) 2019
+ * Written by Alex Bennée <alex.bennee@linaro.org>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#define SYS_WRITE0      0x04
+#define SYS_REPORTEXC   0x18
+
+#include <stdint.h>
+#include "semicall.h"
+
+int main(int argc, char *argv[argc])
+{
+#if UINTPTR_MAX == UINT32_MAX
+    uintptr_t exit_code = 0x20026;
+#else
+    uintptr_t exit_block[2] = {0x20026, 0};
+    uintptr_t exit_code = (uintptr_t) &exit_block;
+#endif
+
+    __semi_call(SYS_WRITE0, (uintptr_t) "Hello World");
+    __semi_call(SYS_REPORTEXC, exit_code);
+    /* if we get here we failed */
+    return -1;
+}