Deprecate and obsolete OldSize

Summary

Deprecate the OldSize flag in JDK 23 and obsolete it in JDK 24, then remove in JDK 25.

Problem

Due to the intrinsic constraint: NewSize + OldSize == InitialHeapSize, if users specify all three flags with improper values, thereby violating this constraint, one flag value must be discarded. Discarding any one of them might come as a surprise to users.

Solution

Deprecate the OldSize flag in JDK 23 and obsolete it in JDK 24, then remove in JDK 25.

Specification

   product(size_t, OldSize, ScaleForWordSize(4*M),                           \
-          "Initial tenured generation size (in bytes)")                     \
+          "(Deprecated) Initial tenured generation size (in bytes)")        \
           range(0, max_uintx)                                               \