[clang] [Driver] Clean up fp-contract handling in clang driver (PR #91271)

[Fangrui Song via cfe-commits]

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@@ -238,3 +238,17 @@
 // RUN: %clang -### -fno-unsafe-math-optimizations -funsafe-math-optimizations \
 // RUN: -ffp-contract=off -c %s 2>&1 | FileCheck --check-prefix=CHECK-FPC-OFF %s
 
+// RUN: %clang -### -funsafe-math-optimizations -ffp-contract=off -c %s 2>&1 \
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MaskRay wrote:

L161 has similar `-funsafe-math-optimizations -ffp-contract=off` checks. The test can be folded there.

https://github.com/llvm/llvm-project/pull/91271