Add VSQRT instruction to the integrated ARM assembler.

tests_lit/assembler/arm32/vsqrt.ll

+; Show that we can translate intrinsic vsqrt into a binary instruction.
+
+; REQUIRES: allow_dump
+
+; Compile using standalone assembler.
+; RUN: %p2i --filetype=asm -i %s --target=arm32 --args -Om1 -allow-extern \
+; RUN:   -reg-use s20,d20 | FileCheck %s --check-prefix=ASM
+
+; Show bytes in assembled standalone code.
+; RUN: %p2i --filetype=asm -i %s --target=arm32 --assemble --disassemble \
+; RUN:   --args -Om1 -allow-extern -reg-use s20,d20 \
+; RUN:   | FileCheck %s --check-prefix=DIS
+
+; Compile using integrated assembler.
+; RUN: %p2i --filetype=iasm -i %s --target=arm32 --args -Om1 -allow-extern \
+; RUN:   -reg-use s20,d20 | FileCheck %s --check-prefix=IASM
+
+; Show bytes in assembled integrated code.
+; RUN: %p2i --filetype=iasm -i %s --target=arm32 --assemble --disassemble \
+; RUN:   --args -Om1 -allow-extern -reg-use s20,d20 \
+; RUN:   | FileCheck %s --check-prefix=DIS
+
+declare float @llvm.sqrt.f32(float)
+declare double @llvm.sqrt.f64(double)
+
+define internal float @sqrtFloat() {
+; ASM-LABEL: sqrtFloat:
+; DIS-LABEL: 00000000 <sqrtFloat>:
+; IASM-LABEL: sqrtFloat:
+
+  %v = call float @llvm.sqrt.f32(float 0.5);
+
+; ASM:  vsqrt.f32       s20, s20
+; DIS:    c:    eeb1aaca
+; IASM-NOT: vsqrt.f32
+
+  ret float %v
+}
+
+define internal double @sqrtDouble() {
+; ASM-LABEL: sqrtDouble:
+; DIS-LABEL: 00000030 <sqrtDouble>:
+; IASM-LABEL: sqrtDouble:
+
+  %v = call double @llvm.sqrt.f64(double 0.5);
+
+; ASM:  vsqrt.f64       d20, d20
+; DIS:   38:    eef14be4
+; IASM-NOT: vsqrt.f64
+
+  ret double %v
+}