backend: don't generate the same string literal twice

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -360,7 +360,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
             IrConstKind.Int    -> return LLVMConstInt(LLVMInt32Type(), (value.value as Int).toLong(),   1)
             IrConstKind.Long   -> return LLVMConstInt(LLVMInt64Type(), value.value as Long,             1)
             IrConstKind.String ->
-                return context.staticData.createStringLiteral(value as IrConst<String>).getLlvmValue()
+                return context.staticData.kotlinStringLiteral(value as IrConst<String>).getLlvmValue()
             IrConstKind.Float  -> return LLVMConstRealOfString(LLVMFloatType(), (value.value as Float).toString())
             IrConstKind.Double -> return LLVMConstRealOfString(LLVMDoubleType(), (value.value as Double).toString())
         }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/StaticData.kt

@@ -1,6 +1,7 @@
 package org.jetbrains.kotlin.backend.konan.llvm
 
 import llvm.*
+import org.jetbrains.kotlin.ir.expressions.IrConst
 
 /**
  * Provides utilities to create static data.
@@ -108,4 +109,9 @@ internal class StaticData(override val context: Context): ContextUtils {
 
         return global
     }
+
+    private val stringLiterals = mutableMapOf<String, ConstPointer>()
+
+    fun kotlinStringLiteral(value: IrConst<String>) =
+            stringLiterals.getOrPut(value.value) { createKotlinStringLiteral(value) }
 }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/StaticObjects.kt

@@ -21,7 +21,7 @@ private fun StaticData.staticContainerHeader(): Struct {
     return Struct(runtime.containerHeaderType, Int32(CONTAINER_TAG_NOCOUNT))
 }
 
-internal fun StaticData.createStringLiteral(value: IrConst<String>): ConstPointer {
+internal fun StaticData.createKotlinStringLiteral(value: IrConst<String>): ConstPointer {
     val base64Str = value.value.globalHashBase64
     val valueBytes = value.value.toByteArray(Charsets.UTF_8)