create versioned library name and symlink unversioned name on *nix

This allows executables (e.g. unit tests) to link against the
libunicorn.so in the build directory, after the SONAME was added in
4860fdb3.

Becuase libunicorn.so has an SONAME of libunicorn.so.0, the linker uses
the SONAME for the DT_NEEDED entry of the tests. But because a library
with that name did not exist, they would fail to run.

.gitignore

@@ -4,6 +4,8 @@
 *.o
 *.a
 *.dSYM
+*.so
+*.so.*
 
 qemu/config-all-devices.mak
 

Makefile

@@ -131,7 +131,8 @@ LIBRARY = $(BLDIR)/$(LIBNAME).$(EXT)
 else ifeq ($(IS_CYGWIN),1)
 LIBRARY = $(BLDIR)/$(LIBNAME).$(EXT)
 else	# *nix
-LIBRARY = $(BLDIR)/lib$(LIBNAME).$(EXT)
+LIBRARY = $(BLDIR)/lib$(LIBNAME).$(VERSION_EXT)
+LIBRARY_SYMLINK = $(BLDIR)/lib$(LIBNAME).$(EXT)
 endif
 endif
 
@@ -229,6 +230,9 @@ ifeq ($(V),0)
 else
 	$(CC) $(CFLAGS) $($(LIBNAME)_LDFLAGS) -shared $^ -o $(LIBRARY) $(GLIB) -lm
 endif
+ifneq (,$(LIBRARY_SYMLINK))
+	@ln -sf $(LIBRARY) $(LIBRARY_SYMLINK)
+endif
 endif
 
 $(ARCHIVE): $(UC_TARGET_OBJ) uc.o hook.o