Reinstate strict prototypes warning

[yowl]

This PR reinstates the strict-prototype warning in most places. I wasn't able to do the one in System.IO.Compression

runtime/src/native/libs/System.IO.Compression.Native/CMakeLists.txt

Line 42 in 5481c4b

add_compile_options(-Wno-strict-prototypes)

because of these

/home/scott/github/runtime/src/native/external/zlib/adler32.c(63,15): error G7801012A: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype] [/home/scott/github/runtime/src/native/libs/build-native.proj]
/home/scott/github/runtime/src/native/external/zlib/adler32.c(134,15): error G7801012A: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype] [/home/scott/github/runtime/src/native/libs/build-native.proj]
/home/scott/github/runtime/src/native/external/zlib/adler32.c(143,13): error G7801012A: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype] [/home/scott/github/runtime/src/native/libs/build-native.proj]
/home/scott/github/runtime/src/native/external/zlib/adler32.c(143,13): error G7801012A: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype] [/home/scott/github/runtime/src/native/libs/build-native.proj]
/home/scott/github/runtime/src/native/external/zlib/adler32.c(172,15): error G7801012A: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype] [/home/scott/github/runtime/src/native/libs/build-native.proj]
/home/scott/github/runtime/src/native/external/zlib/adler32.c(180,15): error G7801012A: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype] [/home/scott/github/runtime/src/native/libs/build-native.proj]

Which look like a slightly different problem to the one of a missing void in the .c. function signature. Do you want me to investigate the adler32.c ones more?

This originates from the PR over at dotnet/runtimelab#2004 (comment)

Tested by running

./build.sh -os Browser -configuration Debug

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[yowl]

Thanks @jkotas . Are you expecting it to go through, or do you want me to pick up more of the voids today?

[jkotas]

I can take care of it. I hope that the current CI run will be green.

There is a ton of these warnings in zlib that we want to wait for being fixed in the upstream zlib sources first. So I had to add some of the warning disable command line options back.