This began with a change to support "BRK <operand>" in cc65. The
assembler only supports this for 65816 projects, so we detect that
and enable it when available.
While fiddling with some test code an assertion fired. This
revealed a minor issue in the code analyzer: when overwriting inline
data with instructions, we weren't resetting the format descriptor.
The code that exercises it, which requires two-byte BRKs and an
inline BRK handler in an extension script, has been added to test
2022-extension-scripts.
The new regression test revealed a flaw in the 64tass code
generator's character encoding scanner that caused it to hang.
Fixed.
Also exercise various formatting options.
Also, fix a bug where the code that applies project/platform symbols
to numeric references was ignoring inline data items.
Extension scripts (a/k/a "plugins") can now apply any data format
supported by FormatDescriptor to inline data. In particular, it can
now handle variable-length inline strings. The code analyzer
verifies the string structure (e.g. null-terminated strings have
exactly one null byte, at the very end).
Added PluginException to carry an exception back to the plugin code,
for occasions when they're doing something so wrong that we just
want to smack them.
Added test 2022-extension-scripts to exercise the feature.
