Add Initial support for compact imports proposal. NFC.

So far this is binary-only.  We can add the text format support as
a followup I think.

https://github.com/WebAssembly/compact-import-section

Author: sbc100

src/binaryen-c.cpp

@@ -511,6 +511,9 @@ BinaryenFeatures BinaryenFeatureCustomPageSizes(void) {
 BinaryenFeatures BinaryenFeatureWideArithmetic(void) {
   return static_cast<BinaryenFeatures>(FeatureSet::WideArithmetic);
 }
+BinaryenFeatures BinaryenFeatureCompactImports(void) {
+  return static_cast<BinaryenFeatures>(FeatureSet::CompactImports);
+}
 BinaryenFeatures BinaryenFeatureAll(void) {
   return static_cast<BinaryenFeatures>(FeatureSet::All);
 }

src/binaryen-c.h

@@ -247,6 +247,7 @@ BINARYEN_API BinaryenFeatures BinaryenFeatureRelaxedAtomics(void);
 BINARYEN_API BinaryenFeatures BinaryenFeatureMultibyte(void);
 BINARYEN_API BinaryenFeatures BinaryenFeatureCustomPageSizes(void);
 BINARYEN_API BinaryenFeatures BinaryenFeatureWideArithmetic(void);
+BINARYEN_API BinaryenFeatures BinaryenFeatureCompactImports(void);
 BINARYEN_API BinaryenFeatures BinaryenFeatureAll(void);
 
 // Modules

src/js/binaryen.js-post.js

@@ -195,6 +195,7 @@ function initializeConstants() {
     'RelaxedAtomics',
     'CustomPageSizes',
     'WideArithmetic',
+    'CompactImports',
     'All'
   ].forEach(name => {
     Module['Features'][name] = Module['_BinaryenFeature' + name]();

src/tools/tool-options.h

@@ -113,6 +113,7 @@ struct ToolOptions : public Options {
                   "acquire/release atomic memory operations")
       .addFeature(FeatureSet::CustomPageSizes, "custom page sizes")
       .addFeature(FeatureSet::WideArithmetic, "wide arithmetic")
+      .addFeature(FeatureSet::CompactImports, "compact import section")
       .add("--enable-typed-function-references",
            "",
            "Deprecated compatibility flag",

src/wasm-binary.h

@@ -475,6 +475,7 @@ extern const char* RelaxedAtomicsFeature;
 extern const char* MultibyteFeature;
 extern const char* CustomPageSizesFeature;
 extern const char* WideArithmeticFeature;
+extern const char* CompactImportsFeature;
 
 enum Subsection {
   NameModule = 0,
@@ -1671,6 +1672,12 @@ class WasmBinaryReader {
                           Address defaultIfNoMax);
   void readImports();
 
+  void addImport(uint32_t kind, std::unique_ptr<Importable> importable);
+  std::unique_ptr<Importable>
+  readImportDetails(Name module, Name field, uint32_t kind);
+  std::unique_ptr<Importable> copyImportable(uint32_t kind,
+                                             Importable& details);
+
   // The signatures of each function, including imported functions, given in the
   // import and function sections. Store HeapTypes instead of Signatures because
   // reconstructing the HeapTypes from the Signatures is expensive.

src/wasm-features.h

@@ -59,11 +59,12 @@ struct FeatureSet {
     CustomPageSizes = 1 << 23,
     Multibyte = 1 << 24,
     WideArithmetic = 1 << 25,
+    CompactImports = 1 << 26,
     MVP = None,
     // Keep in sync with llvm default features:
     // https://github.com/llvm/llvm-project/blob/c7576cb89d6c95f03968076e902d3adfd1996577/clang/lib/Basic/Targets/WebAssembly.cpp#L150-L153
     Default = SignExt | MutableGlobals,
-    All = (1 << 26) - 1,
+    All = (1 << 27) - 1,
   };
 
   static std::string toString(Feature f) {
@@ -120,6 +121,8 @@ struct FeatureSet {
         return "multibyte";
       case WideArithmetic:
         return "wide-arithmetic";
+      case CompactImports:
+        return "compact-imports";
       case MVP:
       case Default:
       case All:
@@ -184,6 +187,7 @@ struct FeatureSet {
   bool hasCustomPageSizes() const { return (features & CustomPageSizes) != 0; }
   bool hasMultibyte() const { return (features & Multibyte) != 0; }
   bool hasWideArithmetic() const { return (features & WideArithmetic) != 0; }
+  bool hasCompactImports() const { return (features & CompactImports) != 0; }
   bool hasAll() const { return (features & All) != 0; }
 
   void set(FeatureSet f, bool v = true) {
@@ -213,6 +217,7 @@ struct FeatureSet {
   void setRelaxedAtomics(bool v = true) { set(RelaxedAtomics, v); }
   void setMultibyte(bool v = true) { set(Multibyte, v); }
   void setWideArithmetic(bool v = true) { set(WideArithmetic, v); }
+  void setCompactImports(bool v = true) { set(CompactImports, v); }
   void setMVP() { features = MVP; }
   void setAll() { features = All; }