gdb/

gdb/
	PR breakpoints/12435
	* amd64-tdep.c (amd64_skip_prologue): New variables start_pc_sal,
	next_sal, buf, offset and xmmreg.  Advance PC if it sees the PR.
	* dwarf2read.c (process_full_comp_unit): Initialize
	amd64_prologue_line_bug.
	* symtab.h (struct symtab): New field amd64_prologue_line_bug.

gdb/testsuite/
	PR breakpoints/12435
	* gdb.arch/amd64-prologue-xmm.c: New file.
	* gdb.arch/amd64-prologue-xmm.exp: New file.
	* gdb.arch/amd64-prologue-xmm.s: New file.