When comparing complex numbers create a govalue of the correect type
Implement support for printing complex numbers
Implement negation of complex numbers
Assemble method sets in the order that gccgo uses (unexported methods first)
Use __go_receive instead of __go_receive_big

This runtime function was renamed in the libgo shipped with gcc 4.9.

We may want to consider allowing for multiple versions of libgo, but it may
be easier to closely track gofrontend trunk as we do with LLVM.
Give internal linkage to string constants
Merge pull request #156 from pcc/libgo-complex

Misc fixes pertaining to complex numbers
Merge pull request #160 from pcc/libgo-p4

Align each type's size
Merge pull request #158 from pcc/libgo-p2

Use __go_receive instead of __go_receive_big
Merge pull request #159 from pcc/libgo-p3

Give internal linkage to string constants
Merge pull request #157 from pcc/libgo-p1

Assemble method sets in the order that gccgo uses (unexported methods fi...
Generate debug metadata using DIBuilder

- One DIBuilder per CU
- Pick arbitrary file for synthetic functions
  without location (e.g. ".import"), so there
  are no made up CUs.
Compute sizes and offsets ourselves with padding for embedded structures

The implementation is a tweaked version of the StdSizes implementation which
pads structures to align them. This is similar to what we were previously doing
in llvmTypeMap.Sizeof, but since StdSizes.Offsetsof calls StdSizes.Sizeof
we were getting it wrong when a struct which required padding was embedded
in another struct.
Deduplicate init entries with different priorities by choosing the entry with the highest priority

This can happen in certain obscure cases -- see the comment for more info.
Fix gllgo, enable -g
Merge pull request #149 from axw/libgo-dibuilder

Generate debug metadata using DIBuilder
Merge pull request #161 from pcc/libgo-p1

Compute sizes and offsets ourselves with padding for embedded structures
Merge pull request #162 from pcc/libgo-p2

Deduplicate init entries with different priorities by choosing the entry...
Introduce frame.llvmvalue and port all clients which do not use govalue to it
Modify frame.slice to take llvm.Values instead of govalues