Fixed Clang zealous warnings

imgui.h

@@ -120,6 +120,7 @@ Index of this file:
 #endif
 #pragma clang diagnostic ignored "-Wunknown-pragmas"                // warning: unknown warning group 'xxx'
 #pragma clang diagnostic ignored "-Wold-style-cast"
+#pragma clang diagnostic ignored "-Wfloat-equal"                    // warning: comparing floating point with == or != is unsafe
 #pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
 #pragma clang diagnostic ignored "-Wreserved-identifier"            // warning: identifier '_Xxx' is reserved because it starts with '_' followed by a capital letter
 #elif defined(__GNUC__)