compiler fixes

The compiler flag -s is not necessary and causes build failure on some
systems (macOS, clang compilers) due to it being deprecated.
Additionally, on those same systems, tools/aif2pcm/main.c failed to
compile due to an overly cautious compiler not liking some struct
declarations.
These changes afaik do not affect other builds.

tools/preproc/Makefile

@@ -1,6 +1,6 @@
 CXX := g++
 
-CXXFLAGS := -std=c++11 -O2 -s -Wall -Wno-switch -Werror
+CXXFLAGS := -std=c++11 -O2 -Wall -Wno-switch -Werror
 
 SRCS := asm_file.cpp c_file.cpp charmap.cpp preproc.cpp string_parser.cpp \
 	utf8.cpp