This PR extends CallGraph with functions to return:
- a list of functions in lexicographical order, with respect to
function calls
- the maximum loop nesting depth that a function can be called from
(computed interprocedurally, e.g. if foo() calls bar() at depth 2
and bar() calls baz() at depth 1, the maximum depth of baz() will
be 3).
Adds a fuzzer pass that inserts function calls into the module at
random. Calls from dead blocks can be arbitrary (so long as they do
not introduce recursion), while calls from other blocks can only be to
livesafe functions.
The change fixes some oversights in transformations to replace
constants with uniforms and to obfuscate constants which testing of
this fuzzer pass identified.
huruitao