[base] Make `FT_Hypot' really internal.

* include/freetype/fttrigon.h (FT_Hypot): Move to...
* include/freetype/internal/ftcalc.h: This file.

* src/base/fttrigon.c (FT_Hypot): Move to...
* src/base/ftcalc.c: This file.
Include FT_TRIGONOMETRY_H.

* src/truetype/ttgload.c: Don't include FT_TRIGONOMETRY_H.
6 files changed