Add missing definitions in the stdlib (from stdLibPatches)

[hamzaremmal]

Add all the definitions that we used to patch in the compiler to their actual source file. No more patching.
Since this will be merged during the 3.7.3 cycle, we cannot undo yet the logic, hence, we rely on the facts that:

• None of the changes in this PR are visible during 3.7.3
• Patching is disabled via -Yno-stdlib-patches

Even with all the definitions in the trees, we can still not enable back -Ycheck:all because the trees for Tuple1 and Tuple2 do not contain the definitions of the specialized functions.

Based on #23510

[hamzaremmal]

I already split this into two commits; one where we just copy-paste from the patches and the second (Predef.assert) where we do have a trick to make things work best.
Note that tasty-reader in Scala 2 might need to learn about this trick.