Revert "[Analysis] Guard logf128 cst folding"

This reverts commit 42d3ccc which
caused a test failure.

Author: RoboTux

llvm/lib/Analysis/CMakeLists.txt

@@ -163,6 +163,8 @@ add_llvm_component_library(LLVMAnalysis
   TargetParser
   )
 
-if(LLVM_HAS_LOGF128)
-  target_compile_definitions(LLVMAnalysis PRIVATE HAS_LOGF128)
+include(CheckCXXSymbolExists)
+check_cxx_symbol_exists(logf128 math.h HAS_LOGF128)
+if(HAS_LOGF128)
+ target_compile_definitions(LLVMAnalysis PRIVATE HAS_LOGF128)
 endif()