[clang] [mlir] [llvm] [llvm][TypeSize] Fix addition/subtraction in TypeSize. (PR #72979)

[Guillaume Chatelet via cfe-commits]

gchatelet wrote:

> > The static functions renaming is going to produce a lot of noise but I guess this is too late already... Shall we revert to keep the change minimal? @nikic @paulwalker-arm WDYT ?
> 
> For my money the functions were originally named correctly and then erroneously changed to (a) diverge from the coding standard, and (b) unknowingly introduced a bug caused by the new naming. For both reasons I'm happy to revert to the original naming via this patch.

That would be [my patch](https://reviews.llvm.org/D140263) indeed. Let's revert to the original naming via this patch.

https://github.com/llvm/llvm-project/pull/72979