[WASM] Wasm string.plus optimisations

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

@@ -197,7 +197,7 @@ internal fun jsToKotlinStringAdapter(x: ExternalInterfaceType): String {
     val stringLength = stringLength(x)
     val dstArray = WasmCharArray(stringLength)
     if (stringLength == 0) {
-        return String.unsafeFromCharArray(dstArray)
+        return String(dstArray)
     }
     val maxStringLength = unsafeGetScratchRawMemorySize() / CHAR_SIZE_BYTES
 
@@ -212,7 +212,7 @@ internal fun jsToKotlinStringAdapter(x: ExternalInterfaceType): String {
 
     jsExportStringToWasm(x, srcStartIndex, stringLength - srcStartIndex, memBuffer)
     unsafeRawMemoryToWasmCharArray(memBuffer, srcStartIndex, stringLength - srcStartIndex, dstArray)
-    return String.unsafeFromCharArray(dstArray)
+    return String(dstArray)
 }
 
 

libraries/stdlib/wasm/internal/kotlin/wasm/internal/Number2String.kt

@@ -64,7 +64,7 @@ internal fun itoa32(inputValue: Int, radix: Int): String {
     if (sign == 1)
         buf.set(0, CharCodes.MINUS.code.toChar())
 
-    return String.unsafeFromCharArray(buf)
+    return String(buf)
 }
 
 private fun utoaDecSimple(buffer: WasmCharArray, numInput: Int, offsetInput: Int) {
@@ -144,7 +144,7 @@ internal fun itoa64(inputValue: Long, radix: Int): String {
     if (sign == 1)
         buf.set(0, CharCodes.MINUS.code.toChar())
 
-    return String.unsafeFromCharArray(buf)
+    return String(buf)
 }
 
 // Count number of decimals for u64 values
@@ -178,7 +178,7 @@ internal fun dtoa(value: Double): String {
     val size = dtoaCore(buf, value)
     val ret = WasmCharArray(size)
     buf.copyInto(ret, 0, 0, size)
-    return String.unsafeFromCharArray(ret)
+    return String(ret)
 }
 
 private fun dtoaCore(buffer: WasmCharArray, valueInp: Double): Int {