Using /usr/bin/env tcc doesn't work as it was reported. Revert to
using the full path which fails if the user installs tcc in non-default
location. Then again this is just an example.
This reverts commit 27a428cd0f.
Use @BINDIR@ in shebang of examples to put the right path on the target
system. That is, use #!/usr/local/bin/tcc if tcc is installed in /usr/local/bin
and #!/usr/bin/tcc if tcc is installed in /usr/bin/tcc.