[allocator.requirements] Removed unused variable a3 in Table 27.
[allocator.requirements] Removed unused variable t in Table 27.
[allocator.requirements] Removed unused variables r and s in Table 27.
[allocator.requirements] Removed unused variables V and v in Table 27.
[allocator.requirements] Fixed types for a, a1, a2 in Table 27.

It doesn't make sense to re-use values of type X& when declaring a new
X, as in the use of these variables in Table 28.