node: depends on availability of fpu

node: depends on availability of fpu

It requires either hardware or software emulated fpu, otherwise program
can fail with SIGILL for fp instructions emitted by the JIT compiler

See #1937, #2633, #2442, FS#1257 for details

From code snippet at deps/v8/src/mips/constants-mips.h

    #elif(defined(__mips_soft_float) && __mips_soft_float != 0)
    // This flag is raised when -msoft-float is passed to the compiler.
    // // Although FPU is a base requirement for v8, soft-float ABI is used
    // // on soft-float systems with FPU kernel emulation.
    // const bool IsMipsSoftFloatABI = true;

[1] https://bugs.chromium.org/p/v8/issues/detail?id=4704

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>