32-bit xsave for signal frame update targets the wrong address and clobbers fpu state

I am getting the following test failures on glinux for -m32, both for debug:

```
The following tests FAILED:
74 - code_api|linux.bad-signal-stack (Failed)
159 - code_api|client.signal (Failed)
299 - code_api|api.static_sideline_FLAKY (Failed)
Errors while running CTest

```
... and the following ones for release:

```
The following tests FAILED:
1 - unit_tests (Failed)
38 - code_api|linux.signal0000 (Failed)
39 - code_api|linux.signal0001 (Failed)
40 - code_api|linux.signal0010 (Failed)
41 - code_api|linux.signal0011 (Failed)
42 - code_api|linux.signal0100 (Failed)
43 - code_api|linux.signal0101 (Failed)
44 - code_api|linux.signal0110 (Failed)
45 - code_api|linux.signal0111 (Failed)
46 - code_api|linux.signal1000 (Failed)
47 - code_api|linux.signal1001 (Failed)
48 - code_api|linux.signal1010 (Failed)
49 - code_api|linux.signal1011 (Failed)
50 - code_api|linux.signal1100 (Failed)
51 - code_api|linux.signal1101 (Failed)
52 - code_api|linux.signal1110 (Failed)
53 - code_api|linux.signal1111 (Failed)
54 - code_api|linux.sigplain000 (Failed)
55 - code_api|linux.sigplain001 (Failed)
56 - code_api|linux.sigplain010 (Failed)
57 - code_api|linux.sigplain011 (Failed)
58 - code_api|linux.sigplain100 (Failed)
59 - code_api|linux.sigplain101 (Failed)
60 - code_api|linux.sigplain110 (Failed)
61 - code_api|linux.sigplain111 (Failed)
89 - code_api|pthreads.ptsig (Failed)
158 - code_api|client.signal (Failed)
296 - code_api|api.static_sideline_FLAKY (Failed)
Errors while running CTest

```