Merge wasmtime-jit and wasmtime-profiling (#3247)

* Merge `wasmtime-jit` and `wasmtime-profiling`

This commit merges the `wasmtime-profiling` crate into the
`wasmtime-jit` crate. It wasn't really buying a ton being a separate
crate and an upcoming refactoring I'd like to do is to remove the
`FinishedFunctions` structure. To enable the profilers to work as they
used to this commit changes them to pass `CompiledModule` as the
argument, but this only works if the profiling trait can see the
`CompiledModule` type.

* Fix a length calculation

crates/jit/src/profiling.rs

@@ -0,0 +1,67 @@
+use crate::CompiledModule;
+use std::error::Error;
+use std::fmt;
+use wasmtime_environ::{DefinedFuncIndex, EntityRef, Module};
+
+cfg_if::cfg_if! {
+    if #[cfg(all(feature = "jitdump", target_os = "linux"))] {
+        #[path = "profiling/jitdump_linux.rs"]
+        mod jitdump;
+    } else {
+        #[path = "profiling/jitdump_disabled.rs"]
+        mod jitdump;
+    }
+}
+
+cfg_if::cfg_if! {
+    if #[cfg(all(feature = "vtune", target_os = "linux"))] {
+        #[path = "profiling/vtune_linux.rs"]
+        mod vtune;
+    } else {
+        #[path = "profiling/vtune_disabled.rs"]
+        mod vtune;
+    }
+}
+
+pub use jitdump::JitDumpAgent;
+pub use vtune::VTuneAgent;
+
+/// Common interface for profiling tools.
+pub trait ProfilingAgent: Send + Sync + 'static {
+    /// Notify the profiler of a new module loaded into memory
+    fn module_load(&self, module: &CompiledModule, dbg_image: Option<&[u8]>) -> ();
+}
+
+/// Default agent for unsupported profiling build.
+#[derive(Debug, Default, Clone, Copy)]
+pub struct NullProfilerAgent;
+
+#[derive(Debug)]
+struct NullProfilerAgentError;
+
+impl fmt::Display for NullProfilerAgentError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "A profiler agent is not supported by this build")
+    }
+}
+
+// This is important for other errors to wrap this one.
+impl Error for NullProfilerAgentError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        // Generic error, underlying cause isn't tracked.
+        None
+    }
+}
+
+impl ProfilingAgent for NullProfilerAgent {
+    fn module_load(&self, _module: &CompiledModule, _dbg_image: Option<&[u8]>) -> () {}
+}
+
+#[allow(dead_code)]
+fn debug_name(module: &Module, index: DefinedFuncIndex) -> String {
+    let index = module.func_index(index);
+    match module.func_names.get(&index) {
+        Some(s) => s.clone(),
+        None => format!("wasm::wasm-function[{}]", index.index()),
+    }
+}