Enable EHABI by default

After all hard work to implement the EHABI and with the test-suite
passing, it's time to turn it on by default and allow users to
disable it as a work-around while we fix the eventual bugs that show
up.

This commit also remove the -arm-enable-ehabi-descriptors, since we
want the tables to be printed every time the EHABI is turned on
for non-Darwin ARM targets.

Although MCJIT EHABI is not working yet (needs linking with the right
libraries), this commit also fixes some relocations on MCJIT regarding
the EH tables/lib calls, and update some tests to avoid using EH tables
when none are needed.

The EH tests in the test-suite that were previously disabled on ARM
now pass with these changes, so a follow-up commit on the test-suite
will re-enable them.

llvm-svn: 200388
diff --git a/llvm/test/ExecutionEngine/MCJIT/remote/test-fp-no-external-funcs-remote.ll b/llvm/test/ExecutionEngine/MCJIT/remote/test-fp-no-external-funcs-remote.ll
index 5ad7111..8eec0f2 100644
--- a/llvm/test/ExecutionEngine/MCJIT/remote/test-fp-no-external-funcs-remote.ll
+++ b/llvm/test/ExecutionEngine/MCJIT/remote/test-fp-no-external-funcs-remote.ll
@@ -1,6 +1,6 @@
 ; RUN: %lli_mcjit -remote-mcjit -mcjit-remote-process=lli-child-target%exeext %s > /dev/null
 
-define double @test(double* %DP, double %Arg) {
+define double @test(double* %DP, double %Arg) nounwind {
 	%D = load double* %DP		; <double> [#uses=1]
 	%V = fadd double %D, 1.000000e+00		; <double> [#uses=2]
 	%W = fsub double %V, %V		; <double> [#uses=3]
@@ -12,7 +12,7 @@
 	ret double %Y
 }
 
-define i32 @main() {
+define i32 @main() nounwind {
 	%X = alloca double		; <double*> [#uses=2]
 	store double 0.000000e+00, double* %X
 	call double @test( double* %X, double 2.000000e+00 )		; <double>:1 [#uses=0]