Comment 14 for bug 1698539

One possible solution that worked for me is to manually recompile the binaries from the sources with NO_IMPLICIT_EXTERN_C defined.

Steps needed:
- Download and extract the source package
- extract the gcc source package (src/gcc.tar.bz2) somewhere
- Modify the sources that NO_IMPLICIT_EXTERN_C is defined. (I am not sure where the right place is for this definition, so I defined it in gcc/gcc/config/arm/arm.h)
- Repack and replace the gcc source package (src/gcc.tar.bz2)
- Compile the binaries as described in How-to-build-toolchain.pdf

If someone discovers an easier/better way to do this, please don't hesitate to describe it.