phobos unittests not passing with dmd built by clang

[Trass3r]

I changed posix.mak as follows to compile with svn clang:

-HOST_CC=g++
+HOST_CC=clang++

-WARNINGS=-Wno-deprecated -Wstrict-aliasing
+WARNINGS=-Wno-deprecated -Wstrict-aliasing -Wno-logical-op-parentheses

-GFLAGS = $(WARNINGS) -D__near= -D__pascal= -fno-exceptions -O2
+GFLAGS = -x c++ $(WARNINGS) -D__near= -D__pascal= -fno-exceptions -O2


$ make MODEL=64 -f posix.mak -j2 unittest
Testing generated/linux/debug/64/unittest/std/format
several format tests disabled on x86_64 due to bug 5625
core.exception.AssertError at std/format.d(2394): 1.67 -0X1.47AE147AE147BP+0  
-nan
----------------
generated/linux/debug/64/unittest/std/format(onUnittestErrorMsg+0x19)  
[0x4f5801]
generated/linux/debug/64/unittest/std/format(_d_unittest_msg+0x1f)  
[0x4ea1db]
generated/linux/debug/64/unittest/std/format(void  
std.format.__unittest46()+0x17b) [0x4948d3]
generated/linux/debug/64/unittest/std/format(void  
std.format.__modtest()+0x9f) [0x4e58bb]

Testing generated/linux/debug/64/unittest/std/math
core.exception.AssertError at std.math(1891): unittest failure
----------------
generated/linux/debug/64/unittest/std/math(onUnittestErrorMsg+0x19)  
[0x464cf9]
generated/linux/debug/64/unittest/std/math(_d_unittestm+0x28) [0x460c1c]
generated/linux/debug/64/unittest/std/math(void  
std.math.__unittest_fail(int)+0x1d) [0x4601a5]
generated/linux/debug/64/unittest/std/math(void  
std.math.__unittest18()+0x15b) [0x45796f]
generated/linux/debug/64/unittest/std/math(void std.math.__modtest()+0x5e)  
[0x4600ce]



The autotester hasn't revealed this cause it still uses the old g++4.2 on  
OSX.
Apple switched to Clang just recently.

Can anyone confirm this?
If yes, bug in clang, dmd or phobos?