Fixed ModuleInfo generation to no longer use the ModuleInfo class' default initializer for types/defaults, it's unsafe as initializers don't necesarily match the "formal" type. There might be explicit padding. Changed -g switch to emit DW_LANG_D debug info, make demangling work with a patched GDB, still more work to do for full support of D's Dwarf extensions. Added getNullValue helper method.

#ifndef LDC_GEN_AA_H
#define LDC_GEN_AA_H

DValue* DtoAAIndex(Loc& loc, Type* type, DValue* aa, DValue* key, bool lvalue);
DValue* DtoAAIn(Loc& loc, Type* type, DValue* aa, DValue* key);
void DtoAARemove(Loc& loc, DValue* aa, DValue* key);

#endif // LDC_GEN_AA_H