Fix passes to use var names that are valid in C

Author: Smit-create

src/libasr/pass/arr_slice.cpp

@@ -98,7 +98,7 @@ class ReplaceArraySection: public ASR::BaseExprReplacer<ReplaceArraySection> {
     void replace_ArraySection(ASR::ArraySection_t* x) {
         LCOMPILERS_ASSERT(current_scope != nullptr);
         ASR::expr_t* x_arr_var = x->m_v;
-        std::string new_name = "~" + std::to_string(slice_counter) + "_slice";
+        std::string new_name = "__libasr__created__section__" + std::to_string(slice_counter) + "_slice";
         slice_counter += 1;
         char* new_var_name = s2c(al, new_name);
         ASR::ttype_t* slice_asr_type = get_array_from_slice(x, x_arr_var);

src/libasr/pass/pass_utils.cpp

@@ -231,7 +231,7 @@ namespace LCompilers {
         ASR::expr_t* create_var(int counter, std::string suffix, const Location& loc,
                                 ASR::ttype_t* var_type, Allocator& al, SymbolTable*& current_scope) {
             ASR::expr_t* idx_var = nullptr;
-            std::string str_name = "~" + std::to_string(counter) + suffix;
+            std::string str_name = "__libasr__created__var__" + std::to_string(counter) + suffix;
             char* idx_var_name = s2c(al, str_name);
 
             if( current_scope->get_symbol(std::string(idx_var_name)) == nullptr ) {