javadoc issues below:

BufWriter -
reserveSpace - Clarification/Note: Doesn't change the size of buffer. Also, what exceptions are possible (OOM)

patchInt - IndexOutOfBoundsException - Not thrown on RI for wrong offset or wrong size - possible bug (code can be attached)

writeIntBytes - Utility?? consider for API deletion
writeIndex - IllegalArgumentException - consider deletion from doc

ConstantPool -
entryByIndex - For the ConstantPoolException because of unusable index as in Long & Double entries occupy 2 cp slots and the 2nd slot's index is not usable

ClassSignature - 
parseFrom - IAE not recorded

MethodSignature -
parseFrom - IAE not recorded

Signature.ClassTypeSig -
static Signature.ClassTypeSigPREVIEW of(String className,
 Signature.TypeArgPREVIEW... typeArgs) - IAE not recorded

static Signature.ClassTypeSigPREVIEW of(Signature.ClassTypeSigPREVIEW outerType,
 String className,
 Signature.TypeArgPREVIEW... typeArgs) - IAE not recorded