Add no-thumb option for ARMV7 IOS to get it to accept DMB ISH

.travis.yml

@@ -184,7 +184,7 @@ matrix:
       osx_image: xcode10.1
       env:
         - CC="/Applications/Xcode-10.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang"
-        - CFLAGS="-O2 -Wno-macro-redefined -isysroot /Applications/Xcode-10.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.1.sdk -arch arm -miphoneos-version-min=5.1"
+        - CFLAGS="-O2 -mno-thumb -Wno-macro-redefined -isysroot /Applications/Xcode-10.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.1.sdk -arch arm -miphoneos-version-min=5.1"
         - BTYPE="TARGET=ARMV7 HOSTCC=clang NOFORTRAN=1"
 # whitelist
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