Sections now support specifying:
- user IDs
- file offset/size
- alignment
- flags
- bool values for fake, encrypted and thread specific sections

This patch adds the ability to create subsections in a section and
allows permissions to be specified.

ObjectFileJSON sections didn't work, they were set to zero all of the
time. Fixed the bug and fixed the test to ensure it was testing real
values.

Lots of code around LLDB was directly accessing the target's section
load list. This NFC patch makes the section load list private so the
Target class can access it, but everyone else now uses accessor
functions. This allows us to control the resolving of addresses and will
allow for functionality in LLDB which can lazily resolve addresses in
JIT plug-ins with a future patch.

Compared to the python version, this also does type checking and error
handling, so it's slightly longer, however, it's still comfortably
under 500 lines.

Relanding with more explicit type conversions.

This reverts commit f6012a209dca6b1866d00e6b4f96279469884320.

Revert "[lldb] Add cast to fix compile error on 32-but platforms"

This reverts commit d300337e93da4ed96b044557e4b0a30001967cf0.

Revert "[lldb] Improve log message to include missing strings"

This reverts commit 0be33484853557bc0fd9dfb94e0b6c15dda136ce.

Revert "[lldb] Add comment"

This reverts commit e2bb47443d2e5c022c7851dd6029e3869fc8835c.

Revert "[lldb] Implement a formatter bytecode interpreter in C++"

This reverts commit 9a9c1d4a6155a96ce9be494cec7e25731d36b33e.

Compared to the python version, this also does type checking and error
handling, so it's slightly longer, however, it's still comfortably
under 500 lines.

Add support for type summaries embedded into the binary.

These embedded summaries will typically be generated by Swift macros,
but can also be generated by any other means.

rdar://115184658

Section IDs are 64 bit and if a section ID was over 4GB, then the
tabular output of the "target modules dump sections" command would not
align to the column headers. Also if the section type's name was too
long, the output wouldn't algin. This patch fixes this issue.

Old output looked like:
```
(lldb) image dump sections a.out
Sections for '/tmp/a.out' (arm):
  SectID     Type             File Address                             Perm File Off.  File Size  Flags      Section Name
  ---------- ---------------- ---------------------------------------  ---- ---------- ---------- ---------- ----------------------------
  0xffffffffffffffff container        [0x0000000000001000-0x0000000000001010)  rw-  0x00000074 0x00000010 0x00000000 a.out.PT_LOAD[0]
  0x00000001 data             [0x0000000000001000-0x0000000000001010)  rw-  0x00000074 0x00000010 0x00000003 a.out.PT_LOAD[0]..data
  0xfffffffffffffffe container        [0x0000000000001000-0x0000000000001010)  rw-  0x00000084 0x00000000 0x00000000 a.out.PT_TLS[0]
  0x00000002 zero-fill        [0x0000000000001000-0x0000000000001010)  rw-  0x00000084 0x00000000 0x00000403 a.out.PT_TLS[0]..tbss
  0x00000003 regular                                                   ---  0x00000084 0x00000001 0x00000000 a.out..strtab
  0x00000004 regular                                                   ---  0x00000085 0x0000001f 0x00000000 a.out..shstrtab
```
New output looks like:
```
(lldb) image dump sections a.out
Sections for '/tmp/a.out' (arm):
  SectID             Type                   File Address                             Perm File Off.  File Size  Flags      Section Name
  ------------------ ---------------------- ---------------------------------------  ---- ---------- ---------- ---------- ----------------------------
  0xffffffffffffffff container              [0x0000000000001000-0x0000000000001010)  rw-  0x00000074 0x00000010 0x00000000 a.out.PT_LOAD[0]
  0x0000000000000001 data                   [0x0000000000001000-0x0000000000001010)  rw-  0x00000074 0x00000010 0x00000003 a.out.PT_LOAD[0]..data
  0xfffffffffffffffe container              [0x0000000000001000-0x0000000000001010)  rw-  0x00000084 0x00000000 0x00000000 a.out.PT_TLS[0]
  0x0000000000000002 zero-fill              [0x0000000000001000-0x0000000000001010)  rw-  0x00000084 0x00000000 0x00000403 a.out.PT_TLS[0]..tbss
  0x0000000000000003 regular                                                         ---  0x00000084 0x00000001 0x00000000 a.out..strtab
  0x0000000000000004 regular                                                         ---  0x00000085 0x0000001f 0x00000000 a.out..shstrtab
```

In Apple's downstream fork, there is support for understanding the swift
AST sections in various binaries. Even though the lldb on llvm.org does
not have support for debugging swift, I think it makes sense to move
support for recognizing swift ast sections upstream.

Differential Revision: https://reviews.llvm.org/D159142