When comparing complex numbers create a govalue of the correect type
Implement support for printing complex numbers
Implement negation of complex numbers
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
Align each type's size

This is consistent with the other compilers and is in line with what libgo
expects. Fixes a number of memory corruption errors I was seeing in the
libgo tests.
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...
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.