Fix catching number literals immediately followed by &

`mark_end` has to be used with `advance` rather than `skip`, or the
text isn't captured properly in the CST (although the named node may
still exist)

Closes stadelmanma#146

Author: ZedThree

src/scanner.c

@@ -62,23 +62,23 @@ static bool scan_int(TSLexer *lexer) {
     while (iswdigit(lexer->lookahead)) {
         advance(lexer); // store all digits
     }
+    lexer->mark_end(lexer);
 
     // handle line continuations
     if (lexer->lookahead == '&') {
-      skip(lexer);
+      advance(lexer);
       while (iswspace(lexer->lookahead)) {
-        skip(lexer);
+        advance(lexer);
       }
       // second '&' required to continue the literal
       if (lexer->lookahead == '&') {
-        skip(lexer);
+        advance(lexer);
         // don't return here, as we may have finished literal on first
         // line but still have second '&'
         scan_int(lexer);
       }
     }
 
-    lexer->mark_end(lexer);
     return true;
 }
 
@@ -106,11 +106,11 @@ static bool scan_number(TSLexer *lexer) {
             advance(lexer);
             if (lexer->lookahead == '+' || lexer->lookahead == '-') {
                 advance(lexer);
+                lexer->mark_end(lexer);
             }
             if (!scan_int(lexer)) {
                 return true; // valid number token with junk after it
             }
-            lexer->mark_end(lexer);
             lexer->result_symbol = FLOAT_LITERAL;
         }
     }

test/corpus/line_continuations.txt

@@ -273,3 +273,32 @@ end program
         (edit_descriptor)
         (hollerith_constant)))
     (end_program_statement)))
+
+================================================================================
+Line continuation immediately after number literal
+================================================================================
+program test
+  integer :: b(3) = (/&
+  1, &
+  2, &
+  3&
+  /)
+end program test
+--------------------------------------------------------------------------------
+(translation_unit
+  (program
+    (program_statement
+      (name))
+    (variable_declaration
+      (intrinsic_type)
+      (init_declarator
+        (sized_declarator
+          (identifier)
+          (size
+            (number_literal)))
+        (array_literal
+          (number_literal)
+          (number_literal)
+          (number_literal))))
+    (end_program_statement
+      (name))))