Move dw2-producer.* from gdb.arch to gdb.dwarf2 where it was supposed to

be checked in.

diff --git a/gdb/testsuite/gdb.arch/dw2-producer.S b/gdb/testsuite/gdb.dwarf2/dw2-producer.S
similarity index 100%
rename from gdb/testsuite/gdb.arch/dw2-producer.S
rename to gdb/testsuite/gdb.dwarf2/dw2-producer.S

diff --git a/gdb/testsuite/gdb.arch/dw2-producer.exp b/gdb/testsuite/gdb.dwarf2/dw2-producer.exp
similarity index 100%
rename from gdb/testsuite/gdb.arch/dw2-producer.exp
rename to gdb/testsuite/gdb.dwarf2/dw2-producer.exp