There is invalid assembly in dmalloc for PowerPC. The issue is that
'stw' expects a memory operand, and =g constraint allows both registers
and memory. Newer GCC tends to choose register even at -O0, resulting in
invalid assembly. Instead, force a register constraint in 'mflr' and let
GCC decide if it wants to store it into memory at all.
Reported this upstream.
Signed-off-by: Alexey Neyman <stilor@att.net>