arm: switch to hardfloat ABI for Linux

This avoids an error on the Raspberry Pi 3.

.travis.yml

@@ -18,9 +18,9 @@ addons:
     - llvm-7-dev
     - clang-7
     - libclang-7-dev
-    - gcc-arm-linux-gnueabi
+    - gcc-arm-linux-gnueabihf
     - binutils-arm-none-eabi
-    - libc6-dev-armel-cross
+    - libc6-dev-armhf-cross
     - gcc-aarch64-linux-gnu
     - libc6-dev-arm64-cross
     - qemu-system-arm

main_test.go

@@ -68,7 +68,7 @@ func TestCompiler(t *testing.T) {
 				continue // TODO: improve CGo
 			}
 			t.Run(path, func(t *testing.T) {
-				runTest(path, tmpdir, "arm--linux-gnueabi", t)
+				runTest(path, tmpdir, "arm--linux-gnueabihf", t)
 			})
 		}
 
@@ -78,7 +78,7 @@ func TestCompiler(t *testing.T) {
 				continue // TODO: improve CGo
 			}
 			t.Run(path, func(t *testing.T) {
-				runTest(path, tmpdir, "aarch64--linux-gnueabi", t)
+				runTest(path, tmpdir, "aarch64--linux-gnu", t)
 			})
 		}
 	}

target.go

@@ -162,6 +162,9 @@ func LoadTarget(target string) (*TargetSpec, error) {
 			llvmarch = goarch
 		}
 		target = llvmarch + "--" + llvmos
+		if goarch == "arm" {
+			target += "-gnueabihf"
+		}
 		return defaultTarget(goos, goarch, target)
 	}
 
@@ -226,10 +229,10 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 	if goarch != runtime.GOARCH {
 		// Some educated guesses as to how to invoke helper programs.
 		if goarch == "arm" && goos == "linux" {
-			spec.Linker = "arm-linux-gnueabi-gcc"
-			spec.Objcopy = "arm-linux-gnueabi-objcopy"
-			spec.GDB = "arm-linux-gnueabi-gdb"
-			spec.Emulator = []string{"qemu-arm", "-L", "/usr/arm-linux-gnueabi"}
+			spec.Linker = "arm-linux-gnueabihf-gcc"
+			spec.Objcopy = "arm-linux-gnueabihf-objcopy"
+			spec.GDB = "arm-linux-gnueabihf-gdb"
+			spec.Emulator = []string{"qemu-arm", "-L", "/usr/arm-linux-gnueabihf"}
 		}
 		if goarch == "arm64" && goos == "linux" {
 			spec.Linker = "aarch64-linux-gnu-gcc"