Tests: fix GenerateExportHeader directory definitions

There's no need to stringify the values, but instead just pass in
strings. The core problem is that the path may have tokens which are
replaced by the preprocessor which causes an invalid path to be used.

Tests/Module/GenerateExportHeader/CMakeLists.txt

@@ -124,6 +124,6 @@ endif()
 message("#### Testing reference: ${_platform}")
 target_compile_definitions(GenerateExportHeader
   PRIVATE
-    "SRC_DIR=${CMAKE_CURRENT_SOURCE_DIR}/reference/${_platform}"
-    "BIN_DIR=${CMAKE_CURRENT_BINARY_DIR}"
+    "SRC_DIR=\"${CMAKE_CURRENT_SOURCE_DIR}/reference/${_platform}\""
+    "BIN_DIR=\"${CMAKE_CURRENT_BINARY_DIR}\""
 )

Tests/Module/GenerateExportHeader/exportheader_test.cpp

@@ -136,13 +136,10 @@ int main()
   libstatic_not_exported();
   libstatic_excluded();
 
-#define STRINGIFY_IMPL(A) #A
-#define STRINGIFY(A) STRINGIFY_IMPL(A)
-
-  compare(STRINGIFY(SRC_DIR) "/libshared_export.h",
-          STRINGIFY(BIN_DIR) "/libshared/libshared_export.h");
-  compare(STRINGIFY(SRC_DIR) "/libstatic_export.h",
-          STRINGIFY(BIN_DIR) "/libstatic/libstatic_export.h");
+  compare(SRC_DIR "/libshared_export.h",
+          BIN_DIR "/libshared/libshared_export.h");
+  compare(SRC_DIR "/libstatic_export.h",
+          BIN_DIR "/libstatic/libstatic_export.h");
 
   return 0;
 }