Add test for #14797: internalAstError with if in do while loop (#8725)

Fixed in 42a0805.

Author: ludviggunne

test/testtokenize.cpp

@@ -92,6 +92,7 @@ class TestTokenizer : public TestFixture {
         TEST_CASE(tokenize40);  // #13181
         TEST_CASE(tokenize41);  // #13847
         TEST_CASE(tokenize42);  // #13861
+        TEST_CASE(tokenize43);  // #13861
 
         TEST_CASE(validate);
 
@@ -941,6 +942,12 @@ class TestTokenizer : public TestFixture {
         (void)errout_str();
     }
 
+    void tokenize43() {
+        const char code[] = "void f(int i) { do if (i &= 1) {} while (0); }";
+        ASSERT_NO_THROW(tokenizeAndStringify(code));
+        (void)errout_str();
+    }
+
     void validate() {
         // C++ code in C file
         ASSERT_THROW_INTERNAL(tokenizeAndStringify(";using namespace std;",dinit(TokenizeOptions, $.expand = false, $.cpp = false)), SYNTAX);