RFR: 8315771: [JVMCI] Resolution of bootstrap methods with int[] static arguments [v8]

[Sacha Coppey]

> Currently, `jdk.vm.ci.meta.ConstantPool.lookupBootstrapMethodInvocation` does not support static arguments of type `int[]`.
> 
> Supporting those static arguments allows to correctly lookup the `BootstrapMethodInvocation` of some `InvokeDynamic` and `DynamicConstant`.
> 
> To lookup the constant at the index in the static arguments index list, a new class is introduced, allowing to lazily resolve the constant or obtain the constant pool index of the arguments:
> 
> 
>     static class CachedBSMArgs extends AbstractList<JavaConstant> {
>         private final JavaConstant[] cache;
>         private final HotSpotConstantPool cp;
>         private final int bssIndex;
> 
>         CachedBSMArgs(HotSpotConstantPool cp, int bssIndex, int size) {
>             this.cp = cp;
>             this.bssIndex = bssIndex;
>             this.cache = new JavaConstant[size];
>         }
> 
>         @Override
>         public JavaConstant get(int index) {
>             JavaConstant res = cache[index];
>             if (res == null) {
>                 int argCpi = compilerToVM().bootstrapArgumentIndexAt(cp, bssIndex, index);
>                 res = compilerToVM().lookupConstantInPool(cp, argCpi, false);
>                 if (res == null) {
>                     res = JavaConstant.forInt(argCpi);
>                 }
>                 cache[index] = res;
>             }
>             return res;
>         }
> 
>         @Override
>         public int size() {
>             return cache.length;
>         }
>     }

Sacha Coppey has updated the pull request incrementally with one additional commit since the last revision:

  Add undefined behavior documentation for bootstrapArgumentIndexAt and update documentation for @return of CachedBSMArgs.get

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15588/files
  - new: https://git.openjdk.org/jdk/pull/15588/files/d6aa5934..d75e0926

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15588&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15588&range=06-07

  Stats: 6 lines in 2 files changed: 4 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/15588.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15588/head:pull/15588

PR: https://git.openjdk.org/jdk/pull/15588