softmmu: introduce cpu_ldst.h

This will collect all load and store helpers soon.  For now
it is just a replacement for softmmu_exec.h, which this patch
stops including directly, but we also include it where this will
be necessary in order to simplify the next patch.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/target-i386/fpu_helper.c b/target-i386/fpu_helper.c
index a04e754..1b2900d 100644
--- a/target-i386/fpu_helper.c
+++ b/target-i386/fpu_helper.c
@@ -22,10 +22,7 @@
 #include "exec/helper-proto.h"
 #include "qemu/aes.h"
 #include "qemu/host-utils.h"
-
-#if !defined(CONFIG_USER_ONLY)
-#include "exec/softmmu_exec.h"
-#endif /* !defined(CONFIG_USER_ONLY) */
+#include "exec/cpu_ldst.h"
 
 #define FPU_RC_MASK         0xc00
 #define FPU_RC_NEAR         0x000