* app/composite/gimp-composite-sse2.c:
Trying to be more flexible in register use so the compiler can do
reloads without running out of registers when using optimisation
modes other than 2.

Avoid the message "error: can't find a register in class
`GENERAL_REGS' while reloading `asm'"

* app/composite/gimp-composite-x86.h
Use more newlines in asm() macros to ensure that gcc gets the
instruction count correct.  This is partially complete as of this
commit.