[MCJIT] In debug memory dump output, don't truncate 64 bit addresses

Summary: In dumpMemorySections a cast was too short, and in resolveRelocations a format string was too short.

Test Plan:
Enable debug build and run a program which invokes MCJIT::finalizeObject(). Saw valid input as below (highlighted addresses were previously truncated):

```
Parse relocations:
Resolving relocations Section #0	**0x7f4c1337b000**
----- Contents of section socket1 before relocations -----
**0x00007f4c1337b000**: 18 01 00 00 01 01 01 0a 00 00 00 00 04 03 02 01
0x00007f4c1337b010: 7b 1a f8 ff 00 00 00 00 18 11 00 00 05 00 00 00

```

Reviewers: lhames

Reviewed By: lhames

Subscribers: llvm-commits, ast

Differential Revision: http://reviews.llvm.org/D8681

llvm-svn: 233512