Fixed unit-test env var list parsing and improved filtered test run speed (#1626)

* Fixed parsing of env var lists which were overwriting the mutable env var string and polluting future parses.

* Fixed all tests to obey UT_DATATYPES and UT_REDOPS filters.

* Allow tests to bail early via `GTEST_SKIP` if UT_DATATYPES or UT_REDOPS filters give a test size of zero. This allows tests to run much faster with filters on.

* Wrapped the support checks in helper functions on `TestBed`.

test/SendRecvTests.cpp

@@ -12,12 +12,19 @@ namespace RcclUnitTesting
     TestBed testBed;
 
     // Configuration
-    std::vector<ncclDataType_t> const& dataTypes       = {ncclInt32, ncclFloat16, ncclFloat64};
+    std::vector<ncclDataType_t> const& testDataTypes   = {ncclInt32, ncclFloat16, ncclFloat64};
     std::vector<int>            const  numElements     = {1048576, 53327, 1024, 0};
     bool                        const  inPlace         = false;
     bool                        const  useManagedMem   = false;
 
     OptionalColArgs options;
+
+    std::vector<ncclDataType_t> dataTypes;
+    testBed.GetSupportedDataTypes(dataTypes, testDataTypes);
+    if (dataTypes.empty()) {
+      GTEST_SKIP() << "Skipping... test datatypes excluded by UT_DATATYPES.";
+    }
+
     bool isCorrect = true;
     int numGpus = testBed.ev.maxGpus;
     for (int rpg=0; rpg < 2 && isCorrect; ++rpg)
@@ -104,13 +111,20 @@ namespace RcclUnitTesting
     TestBed testBed;
 
     // Configuration
-    std::vector<ncclDataType_t> const& dataTypes       = {ncclInt32, ncclFloat16, ncclFloat64};
+    std::vector<ncclDataType_t> const& testDataTypes   = {ncclInt32, ncclFloat16, ncclFloat64};
     std::vector<int>            const  numElements     = {1048576, 53327, 1024};
     bool                        const  inPlace         = false;
     bool                        const  useManagedMem   = false;
     bool                        const  userRegistered  = true;
 
     OptionalColArgs options;
+
+    std::vector<ncclDataType_t> dataTypes;
+    testBed.GetSupportedDataTypes(dataTypes, testDataTypes);
+    if (dataTypes.empty()) {
+      GTEST_SKIP() << "Skipping... test datatypes excluded by UT_DATATYPES.";
+    }
+
     bool isCorrect = true;
     int numGpus = testBed.ev.maxGpus;
     for (int rpg=0; rpg < 2 && isCorrect; ++rpg)