Trying to get the alignment right by using the first non-default one
in the following order of descending priority:
VarDeclaration::alignment [variables only of course]
Type::alignment()
Type::alignsize()
This fixes `align(x) struct S { ... }`.
Now with *almost* working EH codegen. Does not compile Phobos yet
because we run into the "instruction does not dominate all uses"
issue when an r-value result of toElemDtor is used and we need to
run cleanups in between. Should easily be fixed by promoting those
values to allocas.
Most of the changes outside of ir/irfunction.{h, cpp} are just
because CreateCallOrInvoke moved locations. I took the
opportunity to also make use of the different arg count
overloads where possible.
The new type parameter for `llvm::ConstantExpr::getGetElementPtr()` is
checked for being the pointee of the provided base (or more precisely,
the pointee of the base's scalar type).
So for the 'ugly' GEP, i8* as type for an i8* base was clearly wrong,
and the 'nice' GEP with the fixed i8 type would only work for i8* bases.
This fixes dmd-testsuite issues on Win64, e.g., runnable/test11.d.
