Skip `-m32` build-test on non-Linux non-x86 platforms (#2558)
Skip `-m32` build-test on non-Linux non-x86 platforms (#2558)

The `-m32/64` compiler flags are x86/64-specific (mostly; at least in the
context of JerryScript-supported architectures) and macOS has deprecated 32-bit
support, so it's better to keep the build-testing of `-m32` to x86[-64]/Linux
only.

JerryScript-DCO-1.0-Signed-off-by: Renata Hodovan reni@inf.u-szeged.hu
jerryscript-project/jerryscript,akosthekiss/jerryscript,zherczeg/jerryscript,akosthekiss/jerryscript,robertsipka/jerryscript,gabrielschulhof/jerryscript,jerryscript-project/jerryscript,zherczeg/jerryscript,robertsipka/jerryscript,bzsolt/jerryscript,dbatyai/jerryscript,gabrielschulhof/jerryscript,gabrielschulhof/jerryscript,jerryscript-project/jerryscript,robertsipka/jerryscript,zherczeg/jerryscript,robertsipka/jerryscript,robertsipka/jerryscript,dbatyai/jerryscript,jerryscript-project/jerryscript,bzsolt/jerryscript,dbatyai/jerryscript,bzsolt/jerryscript,gabrielschulhof/jerryscript,akosthekiss/jerryscript,bzsolt/jerryscript,robertsipka/jerryscript,jerryscript-project/jerryscript,akosthekiss/jerryscript,dbatyai/jerryscript,gabrielschulhof/jerryscript,bzsolt/jerryscript,zherczeg/jerryscript,zherczeg/jerryscript,dbatyai/jerryscript,akosthekiss/jerryscript