rename avx2_gather.cc -> gather.cc

bochs/cpu/Makefile.in

@@ -62,7 +62,7 @@ OBJS = \
 	avx.o \
 	avx_pfp.o \
 	avx2.o \
-	avx2_gather.o \
+	gather.o \
 	bmi32.o \
 	xsave.o \
 	aes.o \
@@ -243,7 +243,7 @@ avx2.o: avx2.@CPP_SUFFIX@ ../bochs.h ../config.h ../osdep.h \
  descriptor.h instr.h ia_opcodes.h lazy_flags.h icache.h apic.h i387.h \
  ../fpu/softfloat.h ../fpu/tag_w.h ../fpu/status_w.h ../fpu/control_w.h \
  xmm.h vmx.h stack.h simd_int.h
-avx2_gather.o: avx2_gather.@CPP_SUFFIX@ ../bochs.h ../config.h ../osdep.h \
+gather.o: gather.@CPP_SUFFIX@ ../bochs.h ../config.h ../osdep.h \
  ../bx_debug/debug.h ../config.h ../osdep.h ../gui/siminterface.h \
  ../cpudb.h ../gui/paramtree.h ../memory/memory.h ../pc_system.h \
  ../gui/gui.h ../instrument/stubs/instrument.h cpu.h cpuid.h crregs.h \