Made the following changes:
 * Changed our multi-line strings to use C++11 raw string literals
 * Added argument-less macros for checking if GL or EGL had an error.
 * Made checkCompileFails return the error log, in case a test wants to
   ensure a specific failure is reported.
 * Made some more tests use the new MakeShader function.

Bug chromium:977665

Change-Id: I5a410d88449d1349806215bd21bb8c2b6d7acc56
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33268
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Tested-by: Sean Risser <srisser@google.com>