Issue 1:
I see this failure with Fedora nightlies with LLVM 3.4. It has been introduced over the last two or three weeks. See also #11760 : I'm not sure when one or the other happens, but these are on two different distro versions.

/builddir/build/BUILD/julia/build/usr/bin/julia --check-bounds=yes --startup-file=no ./runtests.jl all
From worker 3: * linalg2 in 85.89 seconds
From worker 3: * linalg3 in 41.05 seconds
From worker 2: * linalg1 in 143.13 seconds
From worker 3: * linalg4 in 22.66 seconds
From worker 2: * linalg/lapack in 37.76 seconds
From worker 2: * linalg/tridiag in 22.18 seconds
From worker 2: * linalg/bidiag in 28.83 seconds
From worker 2: * linalg/diagonal in 32.03 seconds
From worker 2: * linalg/pinv in 13.75 seconds
From worker 2: * linalg/givens in 2.80 seconds
From worker 2: * linalg/cholesky in 23.20 seconds
From worker 2: * linalg/lu in 34.96 seconds
From worker 2: * linalg/symmetric in 45.59 seconds
From worker 2: * linalg/arnoldi in 37.17 seconds
From worker 2: * core in 101.81 seconds
From worker 2: * keywordargs in 18.00 seconds
From worker 3: * linalg/triangular in 782.28 seconds
From worker 2: * numbers in 562.26 seconds
From worker 3: * strings in 334.97 seconds
From worker 3: * dict in 101.83 seconds
From worker 3: * hashing in 250.45 seconds
From worker 3: * remote in 3.56 seconds
From worker 3: * iobuffer in 23.88 seconds
From worker 3: * staged in 24.35 seconds
From worker 2: * dates in 571.13 seconds
From worker 2: * tuple in 39.55 seconds
From worker 3: * arrayops in 601.16 seconds
From worker 3: * reduce in 78.05 seconds
From worker 3: * reducedim in 190.54 seconds
From worker 3: * random in 328.46 seconds
From worker 3: * intfuncs in 36.57 seconds
From worker 3: * simdloop in 23.35 seconds
From worker 3: * blas in 95.02 seconds
From worker 3: * sparse in 642.17 seconds
From worker 2: * subarray in 2389.31 seconds
From worker 2: * copy in 36.57 seconds
From worker 2: * math in 236.53 seconds
From worker 3: * bitarray in 744.55 seconds
From worker 3: * functional in 27.87 seconds
From worker 3: * operators in 7.31 seconds
From worker 3: * path in 18.64 seconds
signal (11): Segmentation fault
sub_fast at ./fastmath.jl:214
jl_apply at /builddir/build/BUILD/julia/src/julia.h:1298
do_call at /builddir/build/BUILD/julia/src/interpreter.c:66
eval at /builddir/build/BUILD/julia/src/interpreter.c:212
jl_interpret_toplevel_expr at /builddir/build/BUILD/julia/src/interpreter.c:28
jl_toplevel_eval_flex at /builddir/build/BUILD/julia/src/toplevel.c:525
jl_eh_restore_state at /builddir/build/BUILD/julia/src/julia.h:1388
jl_f_top_eval at /builddir/build/BUILD/julia/src/builtins.c:569
anonymous at ./test.jl:91
do_test at ./test.jl:49
anonymous at ./no file:156
jl_trampoline at /builddir/build/BUILD/julia/src/builtins.c:965
jl_toplevel_eval_flex at /builddir/build/BUILD/julia/src/toplevel.c:540
jl_toplevel_eval_flex at /builddir/build/BUILD/julia/src/toplevel.c:569
jl_load at /builddir/build/BUILD/julia/src/toplevel.c:616
jl_load_ at /builddir/build/BUILD/julia/src/toplevel.c:622
include at ./boot.jl:254
jl_apply at /builddir/build/BUILD/julia/src/julia.h:1298
runtests at /builddir/build/BUILD/julia/test/testdefs.jl:198
unknown function (ip: -816032829)
jl_apply at /builddir/build/BUILD/julia/src/julia.h:1298
jl_f_apply at /builddir/build/BUILD/julia/src/builtins.c:473
anonymous at ./multi.jl:822
run_work_thunk at ./multi.jl:575
jl_apply at /builddir/build/BUILD/julia/src/julia.h:1298
anonymous at ./multi.jl:822
start_task at /builddir/build/BUILD/julia/src/task.c:234
From worker 2: * fastmath Worker 2 terminated.
ERROR (unhandled task failure): EOFError: read end of file
in yieldto at ./task.jl:21
in wait at ./task.jl:309
in wait at ./task.jl:225
in wait_full at ./multi.jl:558
in remotecall_fetch at ./multi.jl:658
in remotecall_fetch at ./multi.jl:663
in anonymous at ./task.jl:1372
From worker 3: * ccall in 76.12 seconds
ERROR: LoadError: ProcessExitedException()
in yieldto at ./task.jl:21
in wait at ./task.jl:309
in wait at ./task.jl:225
in wait_full at ./multi.jl:558
in remotecall_fetch at ./multi.jl:658
in remotecall_fetch at ./multi.jl:663
in anonymous at ./task.jl:1372
while loading /builddir/build/BUILD/julia/test/runtests.jl, in expression starting on line 5
WARNING: Forcibly interrupting busy workers
WARNING: Unable to terminate all workers
Makefile:9: recipe for target 'all' failed
make[1]: *** [all] Error 1
make[1]: Leaving directory '/builddir/build/BUILD/julia/test'
Makefile:508: recipe for target 'test' failed
make: *** [test] Error 2

https://copr-be.cloud.fedoraproject.org/results/nalimilan/julia-nightlies/fedora-21-i386/julia-0.4.0-0.20150618.fc21/build.log.gz

Issue 2:
On my (Broadwell) machine, using the latest rc:

julia> versioninfo()
Julia Version 0.5.0-rc2+0
Commit 0350e57 (2016-08-12 11:25 UTC)
Platform Info:
System: Darwin (x86_64-apple-darwin13.4.0)
CPU: Intel(R) Core(TM) i5-5287U CPU @ 2.90GHz
WORD_SIZE: 64
BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
LAPACK: libopenblas64_
LIBM: libopenlibm
LLVM: libLLVM-3.7.1 (ORCJIT, broadwell)

julia> @code_native muladd(1.0,2.0,3.0)
.section __TEXT,__text,regular,pure_instructions
Filename: float.jl
pushq %rbp
movq %rsp, %rbp
Source line: 247
mulsd %xmm1, %xmm0
addsd %xmm2, %xmm0
popq %rbp
retq
Source line: 247
nop

The same version built from scratch on my machine:

julia> versioninfo()
Julia Version 0.5.0-rc2+0
Commit 0350e57 (2016-08-12 11:25 UTC)
Platform Info:
System: Darwin (x86_64-apple-darwin15.6.0)
CPU: Intel(R) Core(TM) i5-5287U CPU @ 2.90GHz
WORD_SIZE: 64
BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
LAPACK: libopenblas64_
LIBM: libopenlibm
LLVM: libLLVM-3.7.1 (ORCJIT, broadwell)

julia> @code_native muladd(1.0,2.0,3.0)
.section __TEXT,__text,regular,pure_instructions
Filename: float.jl
pushq %rbp
movq %rsp, %rbp
Source line: 247
vfmadd213sd %xmm2, %xmm1, %xmm0
popq %rbp
retq
Source line: 247
nopl (%rax,%rax)