Three changes:
1. Convert signed integer types to signless versions.
2. Implement the @sext and @zext parameter attributes. Previously the
   type of an function parameter was used to determine whether it should
   be sign extended or zero extended before the call. This information is
   now communicated via the function type's parameter attributes.
3. The interface to LowerCallTo had to be changed in order to accommodate
   the parameter attribute information. Although it would have been
   convenient to pass in the FunctionType itself, there isn't always one
   present in the caller. Consequently, a signedness indication for the
   result type and for each parameter was provided for in the interface
   to this method. All implementations were changed to make the adjustment
   necessary.

llvm-svn: 32788

Supports constant pools
Supports relocations to jump tables
Supports relocations within the data segment (global = address of global)
Allocates memory in a non-hacky for all non-code objects.

llvm-svn: 32430

llvm-svn: 32321

llvm-svn: 31787

llvm-svn: 30240

the file now, however the relocated address is currently wrong.  Fixing
that will require some deep pondering.

llvm-svn: 30207

llvm-svn: 30054

entries in the correct order, fixing several fixmes.

llvm-svn: 29902

right section.

llvm-svn: 29871

does emit linkable .o files in very simple cases.

llvm-svn: 29850