gdb/

gdb/
	* Makefile.in (arm-tdep.o): Update dependencies.
	* arm-tdep.c (thumb_skip_prologue): Remove.
	(thumb_analyze_prologue): New function.
	(arm_skip_prologue): Use thumb_analyze_prologue.
	(thumb_scan_prologue): Ditto.
gdb/testsuite/
	* gdb.arch/thumb-prologue.c, gdb.arch/thumb-prologue.exp: New files.