Allow preprocessor conditionals inside functions

corpus/preprocessor.txt

@@ -109,3 +109,27 @@ General if blocks
   (preproc_if
     (logical_expression (call_expression (identifier) (identifier)) (call_expression (identifier) (identifier)))
     (preproc_def (identifier) (preproc_arg))))
+
+============================================
+Preprocessor conditionals in functions
+============================================
+
+int main() {
+  #if a
+    return 0;
+  #else
+    return 1;
+  #endif
+}
+
+---
+
+(translation_unit
+  (function_definition
+    (identifier)
+    (function_declarator (identifier))
+    (compound_statement
+      (preproc_if (identifier)
+        (return_statement (number_literal))
+        (preproc_else
+          (return_statement (number_literal)))))))

grammar.js

@@ -43,6 +43,7 @@ module.exports = grammar({
       $._preproc_statement,
       $.function_definition,
       $.declaration,
+      $._statement,
       $._empty_declaration,
       $.linkage_specification
     ),
@@ -98,6 +99,7 @@ module.exports = grammar({
     preproc_if: $ => seq(
       '#if',
       $._expression,
+      '\n',
       repeat($._top_level_item),
       optional($.preproc_else),
       '#endif'
@@ -225,11 +227,7 @@ module.exports = grammar({
 
     compound_statement: $ => seq(
       '{',
-      repeat(choice(
-        $.declaration,
-        $._empty_declaration,
-        $._statement
-      )),
+      repeat($._top_level_item),
       '}'
     ),