when x86-64 support was added, "for long double, we use x87 FPU".
And indeed, tests show that Intel's extended precision is used,
not double precision.
long double arguments require 16-byte alignment on the stack, which
requires adjustment when the the stack offset is not an evven number of
8-byte words.
I removed the XMM6/7 registers from the register list because they are not used
on Win64 however they are necessary for parameter passing on x86-64. I have now
restored them but not marked them with RC_FLOAT so they will not be used except
for parameter passing.
Not wise if stddef.h was already included. This is related to commit
3aa26a794e
Instead hack stddef.h to have identical definition and thus
avoid the issue mentionned there.
- add __builtin_va_arg_types to check how arguments were passed
- move most code of stdarg into libtcc1.c
- remove __builtin_malloc and __builtin_free
- add a test case based on the bug report
(http://www.mail-archive.com/tinycc-devel@nongnu.org/msg03036.html)
(Because GNU's alloca.h unconditionally #undef's alloca)
Also, remove gcc specific sections in headers. and
instead change tests such that gcc does not use them.
