docs: fix invalid return value in "Returning errors" example. (expr-l…

…ang#199)

Fix compiler fold optimization of "integer divide by zero"

fix docgen for ambiguous fields on nested structs

fix docgen for ambiguous fields in embedded structs

Add support for maps in len builtin

fix ambiguous embed struct reference

docgen: add package name to types

allow to reuse vm

Output sorted fields in markdown

Fix type check for fast call path