[Wasm] Introduce getWasmAbiVersion to simplify bootstrapping

The intrinsic aims to help with bootstrapping when we need to make changes
in the compiler and in the runtime implementation inside stdlib simultaneously,
allowing to choose behavior depending on the wasmAbiVersion value.

Author: bashor

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/WasmSymbols.kt

@@ -228,6 +228,8 @@ class WasmSymbols(
     val stringGetLiteralLatin1 = getFunction("stringLiteralLatin1", StandardNames.BUILT_INS_PACKAGE_FQ_NAME)
     val stringGetPoolSize = getInternalFunction("stringGetPoolSize")
 
+    val getWasmAbiVersion = getInternalFunction("getWasmAbiVersion")
+
     val testFun = maybeGetFunction("test", kotlinTestPackageFqName)
     val suiteFun = maybeGetFunction("suite", kotlinTestPackageFqName)
     val registerRootSuiteBlock = maybeGetFunction("registerRootSuiteBlock", kotlinTestPackageFqName)

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/BodyGenerator.kt

@@ -1141,6 +1141,10 @@ class BodyGenerator(
                 body.buildConstI32Symbol(wasmFileCodegenContext.stringPoolSize, location)
             }
 
+            wasmSymbols.getWasmAbiVersion -> {
+                body.buildConstI32Symbol(wasmAbiVersion, location)
+            }
+
             wasmSymbols.wasmArrayNewData0 -> {
                 val arrayGcType = WasmImmediate.GcType(
                     wasmFileCodegenContext.referenceGcType(call.typeArguments[0]!!.getRuntimeClass(irBuiltIns).symbol)
@@ -1552,6 +1556,7 @@ class BodyGenerator(
     }
 
     companion object {
+        val wasmAbiVersion = WasmSymbol(0)
         val anyVtableFieldId = WasmSymbol(0)
         val anyITableFieldId = WasmSymbol(1)
         val anyRttiFieldId = WasmSymbol(2)

libraries/stdlib/wasm/internal/kotlin/wasm/internal/Runtime.kt

@@ -120,6 +120,9 @@ internal fun consumeFloatIntoVoid(a: Float): Void =
 internal fun consumeDoubleIntoVoid(a: Double): Void =
     implementedAsIntrinsic
 
+// TODO make intrinsic after bootstrap
+internal fun getWasmAbiVersion(): Int = 0
+
 @ExcludedFromCodegen
 internal fun stringGetPoolSize(): Int =
     implementedAsIntrinsic