Fix #1064 and LINKFLAGS typo for "-static"

[feiyunw]

This PR closes #1064, and #976 if it happens to MinGW only.
I suggest applying PR #1059 's patch before test this one.

Statically linked DLL will not depend on external MinGW DLLs (like libgcc_s_seh-1.dll, libstdc++-6.dll and libwinpthread-1.dll), thus it can be loaded by itself.

BTW, "--static" should be "-static".

FYI:
gcc: -static
ld: -static

[bruvzg]

Probably it should be an option (enabled by default), similar to the Godot build configs:

BoolVariable("use_static_cpp", "Link MinGW/MSVC C++ runtime libraries statically", True)

And also forced for MSVC build:

env.AppendUnique(CCFLAGS=["/MT"])

I'm not sure why we are setting -O3 for debug build, but since it's done for cross-build, it should be the same for native/msys build (or removed from both).

[bruvzg]

I suggest applying PR #1059 's patch before test this one.

A wrong link? This issue seems to be unrelated to static linking.

[feiyunw]

I suggest applying PR #1059 's patch before test this one.

A wrong link? This issue seems to be unrelated to static linking.

Unrelated to this issue, but tools\my_spawn.py has a (deadlock?) bug spoiling MinGW build.

[feiyunw]

I'm not sure why we are setting -O3 for debug build, but since it's done for cross-build, it should be the same for native/msys build (or removed from both).

-O3 is removed.
It is overridden and handled in tools/targets.py

[dsnopek]

Discussed at the GDExtension meeting: overall, we think this makes sense, however, we think it should be an option that is enabled by default as suggested by @bruvzg in an earlier comment.

[dsnopek]

I just tested this one and it fixed the problem for me! I think the only thing that still needs to be done here is adding the option that's enabled by default. If the OP doesn't have time to do this, I may pick it up some time this week.

[akien-mga]

Superseded by #1203. Thanks for the contribution!