RFR: 8034066: Incorrect alignment in the "Code" section for "-c -XDdetails" options [v2]

[Jonathan Lampérth]

> This PR includes changes to ensure `Code:` block indentation in `javap`for the `-verbose` case and non `-verbose` case is the same, which currently does not hold.
> 
> Current behaviour of `javap` differs with and without `-verbose` in the following way:
> **Command**: `javap -c -XDdetails:stackMaps A.class`
> 
> Without `-verbose`
> 
> 
> ...
>   public void a();
>     Code:
>        0: iconst_0
>        1: istore_1
>     StackMap locals:  this int
>     StackMap stack:
> ...
> 
> 
> With `-verbose`
> 
> 
> ...
>   public void a();
>     descriptor: ()V
>     flags: (0x0001) ACC_PUBLIC
>     Code:
>       stack=2, locals=2, args_size=1
>          0: iconst_0
>          1: istore_1
>       StackMap locals:  this int
>       StackMap stack:
> ...
> 
> 
> With `-verbose` all contents of the `Code:` section include an extra (2 space) indent, which is missing in the non `-verbose` case. This is because the `CodeWriter` is called via `CoderWriter.write(...)` in the `-verbose` case, which wraps the `Code:` block in `indent(+1);...indent(-1)`.
> 
> In the non-verbose case this call is circumvented and a simplified version of `CoderWriter.write(...)` is included directly in `ClassWriter.writeMethod`.
> 
> ---
> 
> Alternatively to keep the logic within `CodeWriter` with the goal of keeping the logic for `-verbose` and non `-verbose` in the same place one could add `CodeWriter.writeSimple(...)`.
> 
> 
> void writeSimple(CodeAttribute attr) {
>         println("Code:");
>         indent(+1);
>         writeInstrs(attr);
>         writeExceptionTable(attr);
>         indent(-1);
>     }
> 
> 
> ---
> 
> Note: Test setup is inspired by existing tests: [T6622232.java](https://github.com/openjdk/jdk/blob/master/test/langtools/tools/javap/T6622232.java) and [8244573](https://github.com/openjdk/jdk/blob/master/test/langtools/tools/javap/8244573)

Jonathan Lampérth has updated the pull request incrementally with two additional commits since the last revision:

 - adress feedback in implementation
 - address feedback in tests

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/21685/files
  - new: https://git.openjdk.org/jdk/pull/21685/files/ac915325..bd6372ce

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21685&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21685&range=00-01

  Stats: 382 lines in 5 files changed: 127 ins; 249 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/21685.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21685/head:pull/21685

PR: https://git.openjdk.org/jdk/pull/21685