platforms: Add RISC-V 32-bit and 64-bit platform files (#8403)

Refer to [RISC-V calling
conventions](https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-cc.adoc#cc-type-sizes-and-alignments),
this commit adds platform files for RISC-V 32-bit and 64-bit plarforms.

Author: gagachang

platforms/riscv32.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<platform>
+  <char_bit>8</char_bit>
+  <default-sign>unsigned</default-sign>
+  <sizeof>
+    <bool>1</bool>
+    <short>2</short>
+    <int>4</int>
+    <long>4</long>
+    <long-long>8</long-long>
+    <float>4</float>
+    <double>8</double>
+    <long-double>16</long-double>
+    <pointer>4</pointer>
+    <size_t>4</size_t>
+    <wchar_t>4</wchar_t>
+  </sizeof>
+</platform>

platforms/riscv64.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<platform>
+  <char_bit>8</char_bit>
+  <default-sign>unsigned</default-sign>
+  <sizeof>
+    <bool>1</bool>
+    <short>2</short>
+    <int>4</int>
+    <long>8</long>
+    <long-long>8</long-long>
+    <float>4</float>
+    <double>8</double>
+    <long-double>16</long-double>
+    <pointer>8</pointer>
+    <size_t>8</size_t>
+    <wchar_t>4</wchar_t>
+  </sizeof>
+</platform>

win_installer/cppcheck.wxs

@@ -149,6 +149,8 @@
               <File Id='mips32.xml' Name='mips32.xml' Source='$(var.PtfsDir)\mips32.xml' />
               <File Id='cray_sv1.xml' Name='cray_sv1.xml' Source='$(var.PtfsDir)\cray_sv1.xml' />
               <File Id='msp430_eabi_large_datamodel.xml' Name='msp430_eabi_large_datamodel.xml' Source='$(var.PtfsDir)\msp430_eabi_large_datamodel.xml' />
+              <File Id='riscv32.xml' Name='riscv32.xml' Source='$(var.PtfsDir)\riscv32.xml' />
+              <File Id='riscv64.xml' Name='riscv64.xml' Source='$(var.PtfsDir)\riscv64.xml' />
             </Component>
           </Directory>
           <Directory Id='AddonsFolder' Name='addons'>