Do not duplicate call information in SpecConstr (Trac #8852)
Do not duplicate call information in SpecConstr (Trac #8852)

This long-standing and egregious bug meant that call information was
being gratuitously copied, leading to an exponential blowup in the
number of calls to be examined when function definitions are deeply
nested.  That is what has been causing the blowup in SpecConstr's
running time, not (as I had previously supposed) generating very large code.

See Note [spec_usg includes rhs_usg]

(cherry picked from commit af4bc31c50c873344a2426d4be842f92edf17019)

hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay