[PATCH] test-suite: Fix name clash 'log2'

[robert lytton]

  sorry, the problem was indeed with the macro...

  /home/robert/sandbox/tools_llvm-test-suite/SingleSource/Benchmarks/CoyoteBench/fftbench.cpp:136:23: error: expected ')'
          static size_t log2(size_t n);
                        ^
  /home/robert/sandbox/Installs/Linux/target/include/math.h:253:26: note: expanded from macro 'log2'
  #define log2(x) (log (x) / _M_LOG2_E)
                           ^
  /home/robert/sandbox/tools_llvm-test-suite/SingleSource/Benchmarks/CoyoteBench/fftbench.cpp:136:23: note: to match this '('
  /home/robert/sandbox/Installs/Linux/target/include/math.h:253:17: note: expanded from macro 'log2'
  #define log2(x) (log (x) / _M_LOG2_E)
                  ^
  /home/robert/sandbox/tools_llvm-test-suite/SingleSource/Benchmarks/CoyoteBench/fftbench.cpp:404:23: error: expected ')'
  size_t polynomial<T>::log2(size_t n)
                        ^
  /home/robert/sandbox/Installs/Linux/target/include/math.h:253:26: note: expanded from macro 'log2'
  #define log2(x) (log (x) / _M_LOG2_E)

http://llvm-reviews.chandlerc.com/D2618