This patch adds the EXPR_FIXEDPOINT_LITERAL AST
code to serialize FixedPointLiterals. They were previously
being serialized with the code for integer literals, which
doesn't work properly.
I'm unsure if this is the right location for a new code. This will bump down all the other codes below this and cause any older file to not be read correctly.
Should the file format version number be bumped up?
IIRC the real file format version for this is based on the exact revision of the compiler and there is no pretense of serialized ASTs being sharable between compilers. I don't think we've ever bumped the version number for incompatible changes like this.