Fix #11437 FP knownConditionTrueFalse when comparing clamped value (#8751)

Author: chrchr-github

lib/valueflow.cpp

@@ -4276,6 +4276,7 @@ static void valueFlowAfterAssign(const TokenList &tokenlist,
                         continue;
                     const Token* expr = value.tokvalue;
                     value.intvalue = -value.intvalue;
+                    value.invertBound();
                     value.tokvalue = tok->astOperand1();
 
                     // Skip if it intersects with an already assigned symbol

test/testcondition.cpp

@@ -5244,6 +5244,12 @@ class TestCondition : public TestFixture {
               "    if (c) {}\n"
               "}\n");
         ASSERT_EQUALS("", errout_str());
+
+        check("void f(int a, int b) {\n" // #11437
+              "    a = a < b ? b : a;\n"
+              "    if (a != b) {}\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void alwaysTrueInfer() {