SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
Using `EXPECT_EQ` with boolean literals can cause a warning in certain
versions of GCC. See https://github.com/google/googletest/issues/322
Fixes warnings:
```
../Source/UnitTests/Common/BitSetTest.cpp: In member function 'virtual void BitSet_Basics_Test::TestBody()':
../Source/UnitTests/Common/BitSetTest.cpp:15:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/BitSetTest.cpp: In member function 'virtual void BitSet_BitGetSet_Test::TestBody()':
../Source/UnitTests/Common/BitSetTest.cpp:27:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp: In member function 'virtual void StringUtil_StringBeginsWith_Test::TestBody()':
../Source/UnitTests/Common/StringUtilTest.cpp:23:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp:25:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp:26:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp:27:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp: In member function 'virtual void StringUtil_StringEndsWith_Test::TestBody()':
../Source/UnitTests/Common/StringUtilTest.cpp:35:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp:37:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp:38:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
../Source/UnitTests/Common/StringUtilTest.cpp:39:165: error: converting 'false' to pointer type for argument 1 of 'char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)' [-Werror=conversion-null]
c
```
Pierre Bourdon