Fix various -Wdeprecated-enum-float-conversions around the code

In two cases, it was as easy as replacing an unnamed enum's values
with constexpr variables. In the case of QSimplex, I opted for
qToUnderlying(), as the enum made sense on its own.

Change-Id: Ifcf5be14bd2f35e50adabdbd7ecdb2e83f6bf5b4
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

src/widgets/graphicsview/qsimplex_p.cpp

@@ -551,7 +551,7 @@ qreal QSimplex::solver(SolverFactor factor)
 
     // Return the value calculated by the simplex plus the value of the
     // fixed variables.
-    return (factor * valueAt(0, columns - 1)) + resultOffset;
+    return (qToUnderlying(factor) * valueAt(0, columns - 1)) + resultOffset;
 }
 
 /*!

tests/auto/corelib/global/qrandomgenerator/tst_qrandomgenerator.cpp

@@ -750,18 +750,16 @@ void tst_QRandomGenerator::qualityReal()
         return;
     RandomGenerator rng(control);
 
-    enum {
-        SampleSize = 16000,
+    constexpr int SampleSize = 16000;
 
-        // Expected value: sample size times proportion of the range:
-        PerfectOctile = SampleSize / 8,
-        PerfectHalf = SampleSize / 2,
+    // Expected value: sample size times proportion of the range:
+    constexpr int PerfectOctile = SampleSize / 8;
+    constexpr int PerfectHalf = SampleSize / 2;
 
-        // Variance is (1 - proportion of range) * expected; sqrt() for standard deviations.
-        // Should usually be within twice that and almost never outside four times:
-        RangeHalf = 252,         // floor(4 * sqrt((1 - 0.5) * PerfectHalf))
-        RangeOctile = 167        // floor(4 * sqrt((1 - 0.125) * PerfectOctile))
-    };
+    // Variance is (1 - proportion of range) * expected; sqrt() for standard deviations.
+    // Should usually be within twice that and almost never outside four times:
+    constexpr int RangeHalf = 252;     // floor(4 * sqrt((1 - 0.5) * PerfectHalf))
+    constexpr int RangeOctile = 167;   // floor(4 * sqrt((1 - 0.125) * PerfectOctile))
 
     double data[SampleSize];
     std::generate(std::begin(data), std::end(data), [&rng] { return rng.generateDouble(); });

tests/benchmarks/network/access/qnetworkreply/tst_qnetworkreply.cpp

@@ -631,9 +631,11 @@ void tst_qnetworkreply::uploadPerformance()
       QVERIFY(!QTestEventLoop::instance().timeout());
 }
 
+constexpr qint64 MiB = 1024 * 1024;
+
 void tst_qnetworkreply::httpUploadPerformance()
 {
-      enum {UploadSize = 128*1024*1024}; // 128 MB
+      constexpr qint64 UploadSize = 128 * MiB;
 
       ThreadedDataReaderHttpServer reader;
       FixedSizeDataGenerator generator(UploadSize);
@@ -701,7 +703,7 @@ void tst_qnetworkreply::httpDownloadPerformance()
     QFETCH(bool, serverSendsContentLength);
     QFETCH(bool, chunkedEncoding);
 
-    enum {UploadSize = 128*1024*1024}; // 128 MB
+    constexpr qint64 UploadSize = 128 * MiB;
 
     HttpDownloadPerformanceServer server(UploadSize, serverSendsContentLength, chunkedEncoding);