PEAR/FunctionDeclaration: bug fix - prevent fixer from creating a parse error

Issue as described in 3736.

The fixer would try to remove superfluous whitespace remaining after the move of the opening brace to the previous line, but did not take into account that there may not be any whitespace to removed, i.e. that the `$opener +1` token could be the same as the `$next` token.

Fixed now.

Includes unit test.

Fixes 3736

Author: jrfnl

src/Standards/PEAR/Sniffs/Functions/FunctionDeclarationSniff.php

@@ -308,7 +308,7 @@ public function processMultiLineDeclaration($phpcsFile, $stackPtr, $tokens)
                 $phpcsFile->fixer->addContent($prev, ' {');
 
                 // If the opener is on a line by itself, removing it will create
-                // an empty line, so just remove the entire line instead.
+                // an empty line, so remove the entire line instead.
                 $prev = $phpcsFile->findPrevious(T_WHITESPACE, ($opener - 1), $closeBracket, true);
                 $next = $phpcsFile->findNext(T_WHITESPACE, ($opener + 1), null, true);
 
@@ -324,7 +324,9 @@ public function processMultiLineDeclaration($phpcsFile, $stackPtr, $tokens)
                 } else {
                     // Just remove the opener.
                     $phpcsFile->fixer->replaceToken($opener, '');
-                    if ($tokens[$next]['line'] === $tokens[$opener]['line']) {
+                    if ($tokens[$next]['line'] === $tokens[$opener]['line']
+                        && ($opener + 1) !== $next
+                    ) {
                         $phpcsFile->fixer->replaceToken(($opener + 1), '');
                     }
                 }

src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc

@@ -418,3 +418,12 @@ class ConstructorPropertyPromotionMultiLineAttributesIncorrectIndent
         // Do something.
     }
 }
+
+// Issue #3736 - prevent the fixer creating a parse error by removing the function close brace.
+class Test
+{
+    public function __construct(
+        protected int $id
+    )
+    {}
+}

src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.inc.fixed

@@ -416,3 +416,12 @@ class ConstructorPropertyPromotionMultiLineAttributesIncorrectIndent
         // Do something.
     }
 }
+
+// Issue #3736 - prevent the fixer creating a parse error by removing the function close brace.
+class Test
+{
+    public function __construct(
+        protected int $id
+    ) {
+    }
+}

src/Standards/PEAR/Tests/Functions/FunctionDeclarationUnitTest.php

@@ -99,6 +99,7 @@ public function getErrorList($testFile='FunctionDeclarationUnitTest.inc')
                 371 => 1,
                 402 => 1,
                 406 => 1,
+                428 => 1,
             ];
         } else {
             $errors = [