Added AGI stalls to 486 and later CPUs.

Reworked codegen timing a bit - split timing tables into CPU-specific and generic files.
A few other timing tweaks.

src/Makefile.mingw

@@ -4,7 +4,7 @@ CC   = gcc.exe
 WINDRES = windres.exe
 CFLAGS = -O3 -march=i686 -fomit-frame-pointer -msse2 -mstackrealign -Wall -Werror -fno-strict-aliasing
 OBJ = 386.o 386_dynarec.o 386_dynarec_ops.o 808x.o acer386sx.o ali1429.o amstrad.o cdrom-ioctl.o cdrom-image.o \
-	codegen.o codegen_ops.o codegen_timing_486.o codegen_timing_686.o codegen_timing_pentium.o codegen_timing_winchip.o codegen_x86.o compaq.o config.o cpu.o dac.o \
+	codegen.o codegen_ops.o codegen_timing_486.o codegen_timing_686.o codegen_timing_common.o codegen_timing_pentium.o codegen_timing_winchip.o codegen_x86.o compaq.o config.o cpu.o dac.o \
 	dells200.o device.o disc.o disc_fdi.o disc_img.o disc_sector.o dma.o esdi_at.o fdc.o fdc37c665.o fdd.o fdi2raw.o gameport.o hdd.o hdd_esdi.o hdd_file.o headland.o i430lx.o i430fx.o \
 	i430vx.o ide.o intel.o intel_flash.o io.o jim.o joystick_ch_flightstick_pro.o joystick_standard.o joystick_sw_pad.o joystick_tm_fcs.o keyboard.o keyboard_amstrad.o keyboard_at.o \
 	keyboard_olim24.o keyboard_pcjr.o keyboard_xt.o laserxt.o lpt.o mca.o mcr.o mem.o mfm_at.o mfm_xebec.o model.o mouse.o mouse_ps2.o \