SpeexDSP-1.2.1

• CI: add gitlab CI integration
• fixed-point: Remove unused MULT16_32_Q1[1-4] macros and inlines
• fixed-point: don't truncate 32-bit arg to MULT16_32_Q15
• fixed-point resample: remove 1-bit shift right before interpolation
• fixed-point: introduce MULT16_32_32 to handle unexpected types in MULT16_32_Q15
• Fix incorrect macro names in arch.h
• Remove unused stack_alloc.h
• autotools: do not use deprecated macros

Thanks to Karl Tomlinson, LRFLEW, Luca Barbato and orbea for your contributions.