[js-api] Fix up missing preconditions on allocations (#1793)

Author: bvisness

document/js-api/index.bs

@@ -61,6 +61,9 @@ urlPrefix: https://webassembly.github.io/spec/core/; spec: WebAssembly; type: df
     url: valid/modules.html#valid-module
         text: valid
         text: WebAssembly module validation
+    text: valid limits; url: valid/types.html#valid-limits
+    text: valid memtype; url: valid/types.html#valid-memtype
+    text: valid tabletype; url: valid/types.html#valid-tabletype
     text: module grammar; url: binary/modules.html#binary-module
     text: custom section; url: binary/modules.html#custom-section
     text: customsec; url: binary/modules.html#binary-customsec
@@ -108,9 +111,11 @@ urlPrefix: https://webassembly.github.io/spec/core/; spec: WebAssembly; type: df
     text: global_write; url: appendix/embedding.html#embed-global-write
     text: error; url: appendix/embedding.html#embed-error
     text: store; url: exec/runtime.html#syntax-store
+    text: limits; url: syntax/types.html#syntax-limits
     text: table type; url: syntax/types.html#syntax-tabletype
     text: table address; url: exec/runtime.html#syntax-tableaddr
     text: function address; url: exec/runtime.html#syntax-funcaddr
+    text: memory type; url: syntax/types.html#syntax-memtype
     text: memory address; url: exec/runtime.html#syntax-memaddr
     text: global address; url: exec/runtime.html#syntax-globaladdr
     text: extern address; url: exec/runtime.html#syntax-externaddr
@@ -675,8 +680,8 @@ which can be simultaneously referenced by multiple {{Instance}} objects. Each
     The <dfn constructor for="Memory">Memory(|descriptor|)</dfn> constructor, when invoked, performs the following steps:
     1. Let |initial| be |descriptor|["initial"].
     1. If |descriptor|["maximum"] [=map/exists=], let |maximum| be |descriptor|["maximum"]; otherwise, let |maximum| be empty.
-    1. If |maximum| is not empty and |maximum| &lt; |initial|, throw a {{RangeError}} exception.
-    1. Let |memtype| be { min |initial|, max |maximum| }.
+    1. Let |memtype| be the [=memory type=] { <b>[=limits|min=]</b> |initial|, <b>[=limits|max=]</b> |maximum| }.
+    1. If |memtype| is not [=valid memtype|valid=], throw a {{RangeError}} exception.
     1. Let |store| be the [=surrounding agent=]'s [=associated store=].
     1. Let (|store|, |memaddr|) be [=mem_alloc=](|store|, |memtype|). If allocation fails, throw a {{RangeError}} exception.
     1. Set the [=surrounding agent=]'s [=associated store=] to |store|.
@@ -836,14 +841,16 @@ Each {{Table}} object has a \[[Table]] internal slot, which is a [=table address
         1. [=Throw=] a {{TypeError}} exception.
     1. Let |initial| be |descriptor|["initial"].
     1. If |descriptor|["maximum"] [=map/exists=], let |maximum| be |descriptor|["maximum"]; otherwise, let |maximum| be empty.
-    1. If |maximum| is not empty and |maximum| &lt; |initial|, throw a {{RangeError}} exception.
+    1. Let |type| be the [=table type=] { <b>[=limits|min=]</b> |initial|, <b>[=limits|max=]</b> |maximum| } |elementType|.
+    1. If |type| is not [=valid tabletype|valid=], throw a {{RangeError}} exception.
+
+        Note: Because tables may have up to 2<sup>32</sup> - 1 elements in validation, the checks for [=limits|min=] ≤ 2<sup>32</sup> - 1 and [=limits|max=] ≤ 2<sup>32</sup> - 1 in [=valid limits|limits validation=] cannot fail.
     1. If |value| is missing,
         1. Let |ref| be [=DefaultValue=](|elementType|).
     1. Otherwise,
         1. Let |ref| be [=?=] [=ToWebAssemblyValue=](|value|, |elementType|).
-    1. Let |type| be the [=table type=] {[=table type|min=] |initial|, [=table type|max=] |maximum|} |elementType|.
     1. Let |store| be the [=surrounding agent=]'s [=associated store=].
-    1. Let (|store|, |tableaddr|) be [=table_alloc=](|store|, |type|, |ref|). <!-- TODO(littledan): Report allocation failure https://github.com/WebAssembly/spec/issues/584 -->
+    1. Let (|store|, |tableaddr|) be [=table_alloc=](|store|, |type|, |ref|). If allocation fails, throw a {{RangeError}} exception.
     1. Set the [=surrounding agent=]'s [=associated store=] to |store|.
     1. [=initialize a table object|Initialize=] **this** from |tableaddr|.
 </div>