fix: null-safe bux_strcmp/bux_strncmp/bux_strcpy, init alloca typeName — project build no longer crashes

_selfhost/src/hir_lower.bux

@@ -170,6 +170,7 @@ func Lcx_LowerStmt(ctx: *LowerCtx, stmt: *Stmt) -> *HirNode {
         alloca.column = col;
         alloca.strValue = stmt.strValue;
         // Set type from the declared type expression
+        alloca.typeName = "";
         if stmt.refStmtType != null as *TypeExpr {
             alloca.intValue = stmt.refStmtType.kind;
             alloca.typeName = stmt.refStmtType.typeName;

src_bux/hir_lower.bux

@@ -170,6 +170,7 @@ func Lcx_LowerStmt(ctx: *LowerCtx, stmt: *Stmt) -> *HirNode {
         alloca.column = col;
         alloca.strValue = stmt.strValue;
         // Set type from the declared type expression
+        alloca.typeName = "";
         if stmt.refStmtType != null as *TypeExpr {
             alloca.intValue = stmt.refStmtType.kind;
             alloca.typeName = stmt.refStmtType.typeName;

stdlib/runtime.c

@@ -144,14 +144,21 @@ unsigned int bux_strlen(const char* s) {
 }
 
 int bux_strcmp(const char* a, const char* b) {
+    if (a == b) return 0;
+    if (!a) return -1;
+    if (!b) return 1;
     return strcmp(a, b);
 }
 
 int bux_strncmp(const char* a, const char* b, unsigned int n) {
+    if (a == b) return 0;
+    if (!a) return -1;
+    if (!b) return 1;
     return strncmp(a, b, (size_t)n);
 }
 
 char* bux_strcpy(char* dest, const char* src) {
+    if (!dest || !src) return dest;
     return strcpy(dest, src);
 }