mac-32 nopt builds are broken again

[alexcrichton]

The builders were failing with: LLVM ERROR: Section too large, can't encode r_address (0x10000f3) into 24 bits of scattered relocation entry which generally means that we're generating absurdly large binaries.

Bisection points at e02aa72, which is likely because the entire pretty printer is now generic instead of codegen'd.

cc @eddyb