feat(big): add SBigMul

storm/big/BigStack.cpp

@@ -0,0 +1,29 @@
+#include "storm/big/BigStack.hpp"
+
+BigBuffer& BigStack::Alloc(uint32_t* count) {
+    STORM_ASSERT(this->m_used < SIZE);
+
+    if (count) {
+        (*count)++;
+    }
+
+    auto& buffer = this->m_buffer[this->m_used];
+    this->m_used++;
+
+    return buffer;
+}
+
+void BigStack::Free(uint32_t count) {
+    this->m_used -= count;
+}
+
+BigBuffer& BigStack::MakeDistinct(BigBuffer& orig, int32_t required) {
+    return required ? this->Alloc(nullptr) : orig;
+}
+
+void BigStack::UnmakeDistinct(BigBuffer& orig, BigBuffer& distinct) {
+    if (&orig != &distinct) {
+        orig = distinct;
+        this->Free(1);
+    }
+}