reorganize noreturn,printf,nothrow attributes in funcattr.h
fix empty statement warning
fix warnings
cleanup, use C99
rename error.h to panic.h
iropt: Cmp(Nan, x) localopt rules
arm: arm_cg reorg, initial softfloat support
lower_dw: no need to allocate unnecessary 25% extra
lower_dw: factor out mode==high_signed||mode==high_unsigned test
lower_dw: cleanup, use C99
lower_dw: remove unused def_create_intrinsic_fkt()
lower_dw: make env a static variable

Avoid unnecessary pointer dereferencing.
lower_dw: copy parameters into env struct

Avoid unnecessary pointer dereferencing.
lower_dw: do not guess modes anymore, let backends specify single word modes
be: typedef result proj enum types
arm: cleanup
arm: support different architecture versions
arm: for shifter operands specify the first input number
arm: do not use mode_Iu etc., introduce custom modes
arm: abort if should_be_same is not fulfilled