[libclc] [libclc] Enable -ffp-contract=fast-honor-pragmas globally (PR #153137)

[Wenju He via cfe-commits]

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@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#pragma clang fp contract(off)
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wenju-he wrote:

Verified that exp, trig, and hyperbolic functions (acos acosh acospi asin asinh asinpi atan atan2 atan2pi atanh atanpi cos cosh cospi exp exp10 exp2 expm1 sin sincos sinh sinpi tan tanh tanpi) pass the OpenCL CTS on Intel GPUs with flag "-ffp-contract=fast-honor-pragmas" enabled. Also passes in FTZ mode.
Note: exp/exp2 still require the fixes proposed in https://github.com/llvm/llvm-project/pull/179875; however, those failures are independent of the fp-contract changes in this patch.

https://github.com/llvm/llvm-project/pull/153137