fuzzgen: Generate multiple functions per testcase (#5765)

* fuzzgen: Generate multiple functions per testcase

* fuzzgen: Fix typo

Co-authored-by: Jamey Sharp <jamey@minilop.net>

---------

Co-authored-by: Jamey Sharp <jamey@minilop.net>

cranelift/filetests/src/function_runner.rs

@@ -114,16 +114,16 @@ impl TestFileCompiler {
         Self::with_host_isa(flags)
     }
 
-    /// Registers all functions in a [TestFile]. Additionally creates a trampoline for each one
-    /// of them.
-    pub fn add_testfile(&mut self, testfile: &TestFile) -> Result<()> {
+    /// Declares and compiles all functions in `functions`. Additionally creates a trampoline for
+    /// each one of them.
+    pub fn add_functions(&mut self, functions: &[Function]) -> Result<()> {
         // Declare all functions in the file, so that they may refer to each other.
-        for (func, _) in &testfile.functions {
+        for func in functions {
             self.declare_function(func)?;
         }
 
         // Define all functions and trampolines
-        for (func, _) in &testfile.functions {
+        for func in functions {
             self.define_function(func.clone())?;
             self.create_trampoline_for_function(func)?;
         }
@@ -131,6 +131,20 @@ impl TestFileCompiler {
         Ok(())
     }
 
+    /// Registers all functions in a [TestFile]. Additionally creates a trampoline for each one
+    /// of them.
+    pub fn add_testfile(&mut self, testfile: &TestFile) -> Result<()> {
+        let functions = testfile
+            .functions
+            .iter()
+            .map(|(f, _)| f)
+            .cloned()
+            .collect::<Vec<_>>();
+
+        self.add_functions(&functions[..])?;
+        Ok(())
+    }
+
     /// Declares a function an registers it as a linkable and callable target internally
     pub fn declare_function(&mut self, func: &Function) -> Result<()> {
         let next_id = self.defined_functions.len() as u32;