[TestRaise] Skip the SIGRTMIN test on Android.

[sivachandra]

Summary

Running "kill -l" on nexus player (i386) device results in this:

 1    HUP Hangup                        33     33 Signal 33
 2    INT Interrupt                     34     34 Signal 34
 3   QUIT Quit                          35     35 Signal 35
 4    ILL Illegal instruction           36     36 Signal 36
 5   TRAP Trap                          37     37 Signal 37
 6   ABRT Aborted                       38     38 Signal 38
 7    BUS Bus error                     39     39 Signal 39
 8    FPE Floating point exception      40     40 Signal 40
 9   KILL Killed                        41     41 Signal 41
10   USR1 User signal 1                 42     42 Signal 42
11   SEGV Segmentation fault            43     43 Signal 43
12   USR2 User signal 2                 44     44 Signal 44
13   PIPE Broken pipe                   45     45 Signal 45
14   ALRM Alarm clock                   46     46 Signal 46
15   TERM Terminated                    47     47 Signal 47
16 STKFLT Stack fault                   48     48 Signal 48
17   CHLD Child exited                  49     49 Signal 49
18   CONT Continue                      50     50 Signal 50
19   STOP Stopped (signal)              51     51 Signal 51
20   TSTP Stopped                       52     52 Signal 52 
21   TTIN Stopped (tty input)           53     53 Signal 53
22   TTOU Stopped (tty output)          54     54 Signal 54
23    URG Urgent I/O condition          55     55 Signal 55
24   XCPU CPU time limit exceeded       56     56 Signal 56
25   XFSZ File size limit exceeded      57     57 Signal 57
26 VTALRM Virtual timer expired         58     58 Signal 58
27   PROF Profiling timer expired       59     59 Signal 59
28  WINCH Window size changed           60     60 Signal 60
29     IO I/O possible                  61     61 Signal 61
30    PWR Power failure                 62     62 Signal 62
31    SYS Bad system call               63     63 Signal 63
32     32 Signal 32                     64     64 Signal 64

The signals from 33-64 are missing symbolic names.

lldb/trunk/test/functionalities/signal/raise/TestRaise.py

class RaiseTestCase(TestBase):
     def test_sigstop_with_dwarf(self):
         self.buildDwarf()
         self.signal_test('SIGSTOP', False)
         # passing of SIGSTOP is not correctly handled, so not testing that scenario: https://llvm.org/bugs/show_bug.cgi?id=23574
 
     @skipIfWindows # signals do not exist on Windows
     @dwarf_test
     @skipIfDarwin # darwin does not support real time signals
+    @skipIfTargetAndroid
     def test_sigsigrtmin_with_dwarf(self):
         self.buildDwarf()
         self.signal_test('SIGRTMIN', True)
 
     def launch(self, target, signal):
         # launch the process, do not stop at entry point.
         process = target.LaunchSimple([signal], None, self.get_process_working_directory())
         self.assertTrue(process, PROCESS_IS_VALID)