fix function prototypes in f2c-converted files #511

Job	Run time
build (ubuntu-latest, gfortran, cmake)	14m 10s
build (ubuntu-latest, gfortran, make)	6m 42s
build (ubuntu-latest, flang, cmake)	22m 23s
build (ubuntu-latest, flang, make)	6m 1s
build (macos-latest, gfortran, cmake)	41m 12s
build (macos-latest, gfortran, make)	6m 57s
cross_build (mips64el, mips64el-linux-gnuabi64, DYNAMIC_ARCH=1 TARGET=GENERIC)	6m 8s
cross_build (riscv64, riscv64-linux-gnu, TARGET=RISCV64_GENERIC)	4m 8s
cross_build (mipsel, mipsel-linux-gnu, TARGET=MIPS1004K)	4m 34s
cross_build (alpha, alpha-linux-gnu, TARGET=EV4)	3m 34s
msys2 (MINGW64, int32, Release)	20m 15s
msys2 (MINGW64, int64, Release)	26m 6s
msys2 (MINGW32, int32, Release)	21m 40s
msys2 (CLANG64, int32, Release)	24m 53s
msys2 (CLANG64, int64, Release)	22m 18s
msys2 (CLANG32, int32, Release)	14m 5s
msys2 (MINGW64, int32, None, mingw-w64-x86_64, fc)	17m 54s
	4h 23m 0s

Provide feedback