Add vstr{s,d} to the integrated ARM assembler.

tests_lit/assembler/arm32/vstr.ll

+; Show that we know how to translate (floating point) vstr.
+
+; REQUIRES: allow_dump
+
+; Compile using standalone assembler.
+; RUN: %p2i --filetype=asm -i %s --target=arm32 --args -O2 \
+; RUN:   -reg-use r5,r6,s20,d20 \
+; RUN:   | FileCheck %s --check-prefix=ASM
+
+; Show bytes in assembled standalone code.
+; RUN: %p2i --filetype=asm -i %s --target=arm32 --assemble --disassemble \
+; RUN:   --args -O2 \
+; RUN:   -reg-use r5,r6,s20,d20 \
+; RUN:   | FileCheck %s --check-prefix=DIS
+
+; Compile using integrated assembler.
+; RUN: %p2i --filetype=iasm -i %s --target=arm32 --args -O2 \
+; RUN:   -reg-use r5,r6,s20,d20 \
+; RUN:   | FileCheck %s --check-prefix=IASM
+
+; Show bytes in assembled integrated code.
+; RUN: %p2i --filetype=iasm -i %s --target=arm32 --assemble --disassemble \
+; RUN:   --args -O2 \
+; RUN:   -reg-use r5,r6,s20,d20 \
+; RUN:   | FileCheck %s --check-prefix=DIS
+
+define internal void @testFloat() {
+; ASM-LABEL: testFloat:
+; DIS-LABEL: 00000000 <testFloat>:
+; IASM-LABEL: testFloat:
+
+entry:
+; ASM: .LtestFloat$entry:
+
+  %vaddr = inttoptr i32 0 to float*
+  store float 0.0, float* %vaddr, align 1
+
+; ASM:  vstr    s20, [r5]
+; DIS:  14:     ed96aa00
+; IASM-NOT: vstr
+
+  ret void
+}
+
+define internal void @testDouble() {
+; ASM-LABEL: testDouble:
+; DIS-LABEL: 00000030 <testDouble>:
+; IASM-LABEL: testDouble:
+
+entry:
+; ASM: .LtestDouble$entry:
+
+  %vaddr = inttoptr i32 0 to double*
+  store double 0.0, double* %vaddr, align 1
+
+; ASM:  vstr    d20, [r5]
+; DIS:  3c:     edc54b00
+; IASM-NOT: vstr
+
+  ret void
+}