Don't limit core instances/memories/tables by default (#9257)

This commit updates the defaults of `PoolingAllocationConfig` to allow
unlimited core instances/memories/tables per component instead of the
previous default of 20. The limits here are somewhat restrictive and
more tailored for high-scale use cases which aren't always the best
defaults for a general purpose tool like the `wasmtime` CLI. The CLI for
example uses the pooling allocator by default with `serve` and this
helps accept a wider breadth of components by default instead of
artificially limiting the shape of input components.

crates/wasmtime/src/config.rs

@@ -2704,7 +2704,7 @@ impl PoolingAllocationConfig {
     }
 
     /// The maximum number of core instances a single component may contain
-    /// (default is `20`).
+    /// (default is unlimited).
     ///
     /// This method (along with
     /// [`PoolingAllocationConfig::max_memories_per_component`],
@@ -2720,7 +2720,7 @@ impl PoolingAllocationConfig {
     }
 
     /// The maximum number of Wasm linear memories that a single component may
-    /// transitively contain (default is `20`).
+    /// transitively contain (default is unlimited).
     ///
     /// This method (along with
     /// [`PoolingAllocationConfig::max_core_instances_per_component`],
@@ -2736,7 +2736,7 @@ impl PoolingAllocationConfig {
     }
 
     /// The maximum number of tables that a single component may transitively
-    /// contain (default is `20`).
+    /// contain (default is unlimited).
     ///
     /// This method (along with
     /// [`PoolingAllocationConfig::max_core_instances_per_component`],

crates/wasmtime/src/runtime/vm/instance/allocator/pooling.rs

@@ -153,9 +153,9 @@ impl Default for InstanceLimits {
             total_component_instances: 1000,
             component_instance_size: 1 << 20, // 1 MiB
             total_core_instances: 1000,
-            max_core_instances_per_component: 20,
-            max_memories_per_component: 20,
-            max_tables_per_component: 20,
+            max_core_instances_per_component: u32::MAX,
+            max_memories_per_component: u32::MAX,
+            max_tables_per_component: u32::MAX,
             total_memories: 1000,
             total_tables: 1000,
             #[cfg(feature = "async")]